D.C. all the way.
My favorite heroes there are Batman, Flash, Superman, the Question, and Green Arrow. I also like some Marvel characters(Hulk, Spiderman, Wolverine, Iron Man, and Deadpool.) but Marvel is just a bit too whiny for me. Plus, the villains on D.C. just seem more epic. (Joker, Luthor, Darkseid, Doomsday.) and D.C. has better storylines than Marvel.
Of course, this is just my opinion.