When I pick up a book I don't necessarily think, "The hero has to be just like this!" But there are some things I love in a hero.
Mainly, I'm not too fond of an angsty hero. They're overdone; there's almost too many of them. I like my hero to be a guy who's confident and at times cocky but is an all around nice guy who stands up for what he believes in and does whatever he can to help. He has a few flaws but not enough to make a terribly long list, he has weakness that he is willing to accept, and has some internal conflicts but never questions on which side he stands (in other words, he's all good with almost no trace of evil intentions). When it comes to girls, I'd like to see him courteous, respectful, and maybe even a little shy; I love strong heroes who have something of a fear of love. And, contrary to many, I love a guy who can do the impossible, someone I know would never exist not even in a millions years from now. I'm not saying he has to have powers, but I'd like him to be out of the ordinary. And not everyone loves him: he has to have enemies, a rival, an evil counterpart, and not every ordinary citizen adores him maybe even some who can't stand him.
I think that sums it up. I love all sorts of heroes but one's that are at all like the above are my favorites. Now, as for my heroines, that's a completely different story!