5. The Hulk
Described as rage personified, the Hulk has a huge fanbase of people who can relate to unleashing their rage. Hulk's superhuman strength and resiliance makes him a formitable opponant. As they day, you wouldn't like him when he's angry.
Otherwise known as the Dark Knight, Batman brings a sense of dark brooding that intrigues people. And it doesn't hurt that his alter ego is a multi-millionaire. While batman has no real superpowers, he's got enough gadgets to make any techie envious.
3. Iron Man
What's not to like about a billionaire genius engineer and industrialist playboy who creates a super powered suite of armor to save his like and escape kidnappers? he later uses the suite to fight crime and protect the world against evil as Iron Man. vHis suite is full of cutting edge military grade high tech devices and weapons that allow him to stand up agisnt just about anyone and anything.