Streets of Rage 1 - Adam was the best character in this game, he had the best aerial attack in the game period, and his damage put him well above Blaze and Axel.
Blaze was solid but Axel was really trashy in SoR1.
Streets of Rage 2 - Axel and Max completely owned this game with an Iron Fist.
Axel had the most overpowered move in SoR History, the Grand Upper.
That move had invincibility, did ridiculous damage, and cleared mob area's like their was no tomorrow, plus it had a glitch where you could do it going backwards as well, making it even more beastly. Seriously, you could literally do this move the entire way, and beat SoR2.
Max on the other hand, had HUGE crowd control, and let emphasize this again, Crowd Control is one of the most important aspects of a Side Scrolling beat em up. He did huge damage off of almost anything he did, and his F+A was the single best super special in the game, because on block, it would glitch up and do insane damage, and had ridiculous priority and damage on hit. Not to mention, he was the ultimate with the pipe, oh yeah, Max's slide made up for his slow speed, since you could use that to move around quickly.
Blaze was only decent in this game, she doesn't have really good crowd control, and her Unique attack could get jabbed out of, making it almost useless. She's the best with the dagger though, however with no Grand Upper like Axel, or no insane crowd control and damage like Max, she's not that good.
Skate's abilities where trashy period, and his range left little for you to think about. He wasn't that good in this game at all, so sad, he should of learned a thing or two from his bro, since he was beast in SoR1.
Streets of Rage 3 - Blaze, Zan and Shiva
This is where Blaze is the beast, because she is so versatile, her balanced abilities make her the best over character in the game. She has good priority on all of her abilities, and she's also a monster with the dagger.
Zan is similar in those regards, but with better power, nice range, and great specials.
Shiva was a complete monster in this game...even though he was severely toned down Shiva. His only handicap was that he couldn't pick up weapons. However, he had the elbow attack, which could continuously string against weaker opponents. Really beastly reach, speed, and he was a power attacker, so he could do back throws on even the heaviest opponents.
I really loved Streets of Rage, and SoR2 is imo the best out of them 3, although SoR3 had a better plot and all, SoR2 had Grand Upper and Max, because the removal of Max was not cool, he was too good.