I'm more into the mythos(es?) of heroes than collecting comics, but to me, heroes are heroes whether they come from books, comics, TV, or movies.
And comic book fans go to movies for the same reason any readers do. Who doesn't want to see a big screen interpretation of characters who've lived so vividly in our minds, if only out of curiosity?
I've got to give a thumbs-up to Richard Donner's Superman, Bryan Singer's two X-Men movies, Guillermo del Toro's Hellboy, and the movie of my favorite hero, Daredevil.