This article is not for the "wallet warriors" who sink gobs of their money into the game. They can buy command points as they like and buy heroes as they see fit. They don't have to be stingy with their command points and spend much of their mission time "farming" for CP. This is for those of us who have to squeeze as much out of their precious CPs as they can. We can't buy the 90CP and 135CP heroes with impunity, and we're more likely to buy "cheaper" heroes in the lower levels. This guide will hopefully help you decide which ones to buy early on, and get every bit of effectiveness you can out of your limited CP stash.
Caveats: I'm not an expert on the game (yet). What I write here is based on my own experiences and what I've read on this wiki and in other sources. Your mileage may vary and your opinions and experiences may lead you to different conclusions. That's very cool, and your comments are welcome. Also, I'm not going to talk about higher-level abilities, alternate uniforms, and the like. This is for the lower level player who isn't sure how to maximize his or her game coming out of the gate. And of course it goes without saying that every hero has deficiencies in their statistics that need to be addressed by ISO chipping.
You also get some sort of hero choice for unlocking PVP, I believe, but I'm not sure of the details of that.
Early Days: 15CP
You start with Black Widow, Iron Man and Hawkeye. You quickly come to the conclusion that as good as they may be, they are limited. For one, you only have three of the five character classes covered -- no Bruisers or Scrappers -- and you may suspect, rightly, that there are more capable and powerful heroes out there to be had. But you only have a few CP. What to do? Obviously, you start by going fishing in the shallowest of pools, the 15CP heroes. You may be surprised to find out that some very useful people can be had for very little lucre. In fact, you'll probably get all five fairly quickly, considering two of them are classes you don't have yet.
Cyclops: Probably the best buy of the group. His stats aren't too bad coming out of the gate, so he hits fairly hard and defends fairly well even in the lowest levels. His first two abilities, Optic Blast and Exploit Weakness, are powerful offensive weapons. His Exploit Weakness adds two useful debuffs to the people he cracks in the jaw, something not every Level 2 hero will do for you. He will join Hawkeye as a Tactician, and as time goes on, you may find yourself benching Hawkeye in favor of the one-eyed guy. (Okay, Cyclops has two eyes.) It should be mentioned that with his Level 9 Mega Optic Blast and its three rounds of Incapacitation, Cyclops is regularly used even in the highest levels of PVP play.
Invisible Woman: She has shields, OMG, shields! I wrote a blog post advising lower-level players not to get too fixated on her defensive field. But they are useful for keeping your team alive in the lower levels, especially since no other low-cost hero has that ability. Her stats are fairly weak as she is getting started, and opponents regularly punch through her shields and take her (or your other team members) out. She's an Infiltrator like Black Widow, not the easiest class to learn. Overall well worth the CP.
Iron Fist: Probably the first Scrapper you'll buy. I found him underwhelming in the lower levels, but began learning just what a powerful teammate he can be as he began to stiffen his stats with chips and gaining in ability. His Level 2 Iron Fist attack can be quite potent, especially when combined with his martial arts combo in his one-two attack against Infiltrator opponents. And his Level 6 Healing Chi is very, very welcome during hard-fought battles. Iron Fist, like Cyclops, is a character that will grow with you.
Ms. Marvel: She is pure offense and little defense: a "glass cannon," in the parlance. Coming out of the gate, she hits as hard as anyone, and if you know what's what, you'll get two attacks out of her on her even-numbered rounds: hit first with her Level 2 Kree Strike, and gain an extra attack the next round. She is great for the early levels, but unfortunately loses some of her luster as you progress and gain other Blasters like Dr. Strange and the Human Torch.
She-Hulk: Probably your first Bruiser. She isn't "Hulk Lite," she has her own strengths and weaknesses. I've seen a lot of pixels devoted to downing her as a hero, and I disagree, mostly. She's a tough out in the lower levels, partially because she has good health and attack stats even without chips, and partially because her Level 2 Burst of Speed lets her get two attacks in every other round. You'll quickly figure out just how hard she can hit the first few times you get her Enraged and watch her smack some poor Scrapper out of his or her shoes. As time goes on, you may find She-Hulk spending time on deploys and warming the pine, but she's a good one to get you going, and she always brings a dose of offense to the game.
This is a truly mixed bag. Two Scrappers, one of whom is one of the best in the game (for the CP) and the other one of the most underwhelming; a potent Blaster; a truly excellent Bruiser; and a middling Infiltrator.
Black Cat: The middling Infiltrator. I like the Cat, though I wish she'd zip up her jumpsuit. Her stats for Health and Attack are truly bad at the outset, and need lots of chipping, which means you're spending silver on her just to get her to the point where she can stay alive long enough to make some contributions. Her attacks are quite fierce and well-aimed due to very high Accuracy and Evasion stats, causing a good bit of damage and some fairly severe blood loss among the opposition. I've found that I don't use her regularly, but, well, I just like her. She's like a Scrapper in Infiltrator clothing. (I believe one of her two "alts" makes her a Scrapper. Appropriate.)
Colossus: A real go-to player from the outset. Colossus is a bargain at three times the price. He's the first "tank" hero you'll probably buy -- a Bruiser who has the capability of stepping in the path of single-target attacks and taking reduced damage while your more fragile teammates give the opposition what for. He packs the standard array of Bruiser attacks, and comes out of the gate packing a wallop. You want him, and will probably be fighting with him even as your Agent gets to Level 100 and beyond. He's also immune to bleeding and several other debuffs, making him even more valuable.
Dr. Strange: Another bargain and another long-term investment. Dr. Strange comes out of the gate like an arthritic invalid (poor stats) who can give you a serious and unexpected wallop in the shins with his cane. As he gains in levels, his abilities become more useful, and as you chip him up, he becomes far more tough in battle. He has an excellent healing power at Level 2 and a very potent area attack at Level 6 (which also gives a debuff that damages enemies for several rounds after the initial hit -- very nice). He won't be your first and most powerful blaster after you realize just how limited Iron Man is and start looking for someone else (that will probably be Ms. Marvel), but while the others do the heavy fighting in the lower levels, the Doc can grow and be nurtured into a truly awesome and multi-faceted Blaster. He is also probably the most complex character you'll get at this level, and you'll have to figure out what all that Power of the Principalities stuff is about. You need to; it's important.
Luke Cage: Man, I really want to like Luke. I always like the working-class heroes. But Luke is just not very good at what he does. He's relatively tough out of the gate, but I was surprised at 1) how little damage he does with his attacks, and 2) how little damage he does even after getting leveled and chipped. You need to buy as many heroes as you can get your hands on to progress through the missions, so chances are Luke will end up in your stable, but he really won't give you a lot for your expenditure.
Notes: Nice buff on his L1 attack; when someone that he's attacked attacks him back, he gets a counter. His L9 "tanking" ability doesn't come with a reduction in damage, so it's a good way to get Luke slaughtered while your other guys attack. His best feature may be his immunity to bleeding and such, making him a nice addition when you're fighting enemies that draw a lot of blood.
Sif: She is the flip side of Luke. She is a massively powerful character, especially when you get her chipped and leveled a bit. Her Level 6 Inspire Courage ability gives everyone on your team defensive fortification, and as a resident of downtown Asgard, she doesn't burn, chill, get poisoned, or take radiation damage. And, she hits harder than most Bruisers, leaving behind Bleeding and Ravaged opponents in her wake. She is a go-to hero for the long haul.
Even more mixed results than the previous levels.
Human Torch: Everyone's go-to Blaster at the lower and middle levels. Johnny only attacks with fire, limiting his effectiveness against some opponents and giving him terrific advantages against others such as the Jotun. He may be the first hero you get who spontaneously regenerates some health and stamina, making him much more effective in longer battles. If you remember to get an opponent Burning before you have Johnny hit them with a Fireball, you'll see just how much havoc he can wreak. He won't be your go-to Blaster once you get into the triple-digit levels with your agent, but for the earlier levels, he is a mainstay.
Kitty Pryde: Very unprepossessing at first glance (especially with her relatively weak initial stats), but appearances are deceiving. She is arguably the single most effective Infiltrator in the game, even at the very high levels. Her ability to Phase renders her untouchable by nearly all attacks once she attains that state, and she stays there for two rounds before returning to physical form. Her Level 2 Sneak Attack, delivered after her Level 1 Phased Attack, can smash in the side of a house. Her later abilities are nice, but it's her first two attacks, delivered in tandem, and her phasing that make her so effective in the early and mid levels. Her Shadowcat alt makes her even more formidable.
Mr. Fantastic: Such a disappointment. Reed Richards is a Marvel icon, and his stunning lack of effectiveness as a hero is more than questionable. His attacks, at least until his Level 9 Bifurcator, tend to be very weak, and his health and attack stats are depressingly low. He takes a lot of TLC for a very modest payoff.
Spider-Woman: She joins Luke Cage as a Scrapper who just isn't such a much. All but her first attack are biologically based, rendering her ineffective against some opponents. Her Level 6 Vengeance ability gives her a much-needed counterattack when she is hit, but that's about all she has going for her. Perhaps her best quality lies in the fact that her attacks cost relatively little stamina, so if you can chip up her stamina to acceptable levels, she can last through several rounds of attacks without having to recharge. Still, probably my least favorite hero.
Thing: It just ain't right. Like his compadre Reed, Ben Grimm is one of Marvel's most well-known and beloved characters, and he shouldn't be such a thud in this game. But, he is. His attacks are terribly weak for someone who can, in the comics, throw a train at a bad guy, and he just doesn't get a lot better even as he progresses -- not something you want to see in your Bruisers. His best feature is his bargain-basement price, and that's a shame.
Notes: One of the things I like about Ben is his L2 "stonewall." It makes him a tank, letting him shrug off a (not very big) amount of damage while protecting his team, but better yet, he gets a free attack in return, not necessarily against the guy who smacked him. Not a wonderful ability, but worth noting. Disappointingly, his L1 punch only gets one hit in; he would be far more effective if he got two hits.
You would expect to find more quality and usefulness at this middling level, and you would be right. None of the characters are "bad" per se, and a couple of them are long-haul keepers.
Daredevil: Yet another underwhelming Scrapper, but his ability to dodge attacks and his varied and relatively decent attack continuum make him a fair buy. I doubt you'll play him much at the higher levels, but he will help you get to those levels, which is a benefit in and of itself. Like Quicksilver and the 90CP Spiderman, he can be very tough to hit.
Nightcrawler: Like Dr. Strange and some others, Nightcrawler needs some leveling and TLC before becoming a strong teammate for you. He's an easy out for the opposition in the early going, but give him some time and he will become quite useful, even at higher levels. An Infiltrator, his ability to "teleport" makes him tough to hit, and since all of his attacks are Stealthy, he rarely has to worry about counterattacks and the like. He will never be your main damage-dealer, but he can be an integral part of a successful team, even at middle and high levels.
Quicksilver: I love him when I play him, and I hate him when he is an opponent in PVP. He's like a psychotic mosquito who just won't leave the opposition alone. Because of his incredible speed, he always attacks first, and he attacks a lot, making up in number of attacks what he lacks in single-attack damage. Unusually for a Scrapper, he gets an area attack at Level 2, and his Level 6 One-Mile Punch can be quite fierce. He pops up at even the highest levels. He can make an Infiltrator's life miserable with his Close Quarters Combat ability.
Notes: Watch out, when he attacks an Infiltrator, he ALWAYS follows with an area attack, tagging every one of the opponents. If you're fighting, say, two Bruisers and an Infiltrator, he will rage both Bruisers up before they even take a breath. There are times where it's best to leave Quicksilver home. And there are times when he is a tremendous benefit.
Storm: Yet another character needing TLC before becoming effective. A Blaster, Storm delivers electrical-based attacks in her early going, making her attacks useless against some opponents and quite effective against others. Her Level 2 Protective Shroud is a defensive nicety you'll come to rely on, and her Level 6 Blizzard is a strong area attack, made more so by the fact that very few heroes use cold-based attacks, and many opponents don't defend well against it. Her L9 Tornado is devastating. She always has something of a glass jaw even at the higher levels, but she's a good one to grow with.
War Machine: Oh yeah ... ladies and gentlemen, Lieutenant Colonel James Rhodes on the Mini-Gun. Don't forget to tip your waiter, if anything is left standing after his performance. War Machine, like Ms. Marvel, is all offense and not much defense. His Level 1 Blade Punch is stunningly powerful (assuming the opponent isn't immune or resistant to energy attacks). I rarely use his Level 2 Repulsor Ray -- under most circumstances, the Blade Punch is better and costs less stamina. And the Mini-Gun, if you give it a round to become fully charged, can be a thing of terrible beauty, mowing down opponents like ripe wheat. But he takes a lot of damage, and as a Tactician is easily taken down by an irate and powerful Infiltrator. He needs a lot of chipping and leveling before he comes into his own. (Because of his lousy defense, and because my Agent became a Tactician, I benched WM for a good while. After earning a bit of gold in PVP, I bought him some new chips and am now playing him again, though not as regularly as I once did.)
Quite a few of these heroes become even more powerful after you get to the point where you can "alt" them: Cyclops, Invisible Woman, Kitty Pryde (Shadowcat), Quicksilver, and War Machine (Iron Patriot) all come to mind, along with a couple of others in the above listing. But unless you're spending more money than I can, you won't get to that point for a while. What you do need is a balanced set of heroes: several go-to guys in each class who will get you to the point where you have the CP to buy the high-dollar heroes. Strictly from the above listing, I would recommend the following as your early stable. (You are more than free to disagree and go your own way.)
Blasters: Ms. Marvel, Dr. Strange, Human Torch. (Iron Man was the first hero I "permanently" benched. You need a better Blaster. Even given the fact that, after some preparation, his Level 9 Unibeam can melt a jumbo jet, he just isn't the Blaster I need for my team unless I want to spend a lot of resources chipping him up and buying him a spiffy alt uniform. When you're able, leave Tony Stark to help run SHIELD.)
Bruisers: Colossus, She-Hulk. (There are reasons to buy Thing outside of his effectiveness as a hero, i.e. the fact that he is needed for some mission deploys and to unlock an Epic Boss fight, but otherwise he just isn't worth the recommendation. Save your CP for a truly effective bruiser such as Captain Britain.)
Infiltrators: Kitty Pryde, Invisible Woman, Nightcrawler. (Don't give up on Black Widow. She can be a powerful character in her own right, especially after gaining her Level 6 attack that removes buffs from those she hits with it, and even more so after you get to the point where you can outfit her in her gray alternate Tactician uniform.)
Scrappers: Sif, Iron Fist, Quicksilver. (Knowing what I know now, Sif would have been my first purchase as a player.)
Tacticians: Cyclops, War Machine. (Honestly, outside of deploys and mission unlocks, the only reason I can see to have Mr. Fantastic is to have enough heroes in your stable to get to the next chapters. I also benched Hawkeye in favor of Cyclops and WM until I learned about his Rapid Fire ability at the higher levels; he sees some action for my guys now.)
That's my opinion. What's yours?