Let's face it, the fact that Feedback won the first season. This is a man whose father committed suicide and who looks up to Stan Lee as a father figure, and who even (in part, at least) got his life together despite his father's suicide thanks thanks to Spider-Man. He also took the competition the most seriously, had consistently strong performances and was sometimes one of only a few contestants who won a challenge (he was one of only four people who managed to reach the door past the attack dogs, and one of only two people who managed not to give away his secret identity in the cafe), and on the rare occasions where he messed up his superhero behavior (like ridiculing Ty'Veculus' costume for example), he took it the hardest. If anyone deserved to win the whole competition, it was him.
Not that the other contestants didn't have awesome moments. Monkey Woman having enough determination to fight attack dogs for 9 minutes and 45 seconds to reach the door for a challenge, for example.
Before that, the Defuser standing up straight and walking with two attack dogs biting onto his arms. This alone probably scored him the win.
In the same attack dog challenge, Ty'Veculus managed to get the fastest time, 16 seconds, with Major Victory not far behind at 17 seconds.
The fact that Iron Enforcer put forth enough of a strong showing that after being eliminated, he was chosen to be the supervillain. Hey, if you can't win every boy's dream of being a superhero, you can have just as much fun being the hammy bad guy!
The "crossing the building to save a damsel in distress" challenge was a rare moment of awesome for all the contestants, because it was the only challenge in the whole first season that nobody failed! In fact, Stan Lee had to make up the "self-nomination" challenge on the spot so he could still come up with a reason to eliminate someone.
In fact, the damsel in distress challenge could also be interpreted as a crowning moment of awesome for Lemuria in particular, since she has a phobia of heights and still managed to pass the challenge.
Lemuria got a crowning moment of awesome that Stan Lee didn't actually intend in the aforementioned "self-nomination challenge"...by figuring out in advance that nominating herself was the correct response, and choosing herself not out of being noble but because she figured out in advance that recommending herself for elimination was precisely what would ensure she wouldn't be eliminated.
Season 2's Final Battle with Dr. Dark. Yes, it was staged, but let's face it, they got to live out just about anyone's childhood fantasy and fight as a superhero they created, complete with their superpowers (which was CGI and they didn't get to see until after editing, but still)!