I'm more of a Marvel guy. I've loved their plot premises much better. If I went with DC it would be The Sandman though. Otherwise Marvel has so many that a favorite is hard. Basically a toss up between Gambit, Thor, and Iron Man.
My favorite superhero is definitely Batman, followed closely by Spider-Man. Your poll list is very DC biased btw. There are a lot of great marvel superheroes; Spider-Man, Iron Man, Wolverine, Daredevil, Captain America, etc.