DC because, at times, they're willing to let their characters grow and evolve.
people inheriting the flash mantle
multiple green lanterns
batman being killed
bringing back krypton
plus I love how epic their stories are at times (superman, green lantern, wonder woman) while they're still able to keep some stories grounded in realism (batman, nightwing)
marvel on the other hand is more grounded in reality, which is good at times, but for now I'm laying off of most of their comics until they reverse Quesada's big "FU I'm in charge so I'll do whatever the **** I want to spider-man decision"