DC has better characters, a better world with a more consistent universe, and more mature and well thought out plot lines. Well, it did until the New52 bullshit anyways.
What does Marvel have going for it? Several big name characters, and a movie studio that knows what the fuck it's doing. Because the Marvel movies have been great, we are all dying for the next one, and rotten tomatoes is going to rip apart Batman vs Superman as bad as they did the Fantastic Four reboot, because DC and Warner bros still, somehow, have no fucking idea how to make a superhero movie!
Answering this question and choosing a side is as painful to me as trying to tear my own arm off. I grew up with both Marvel and DC, and both Marvel and DC have characters I love equally. For example, Marvel have Spider-Man, Captain America and Daredevil. Meanwhile, DC have the Flash, Superman and Batman. Both sides have good story arcs from the comics and good TV shows (Marvels "Agents of S. H. I. E. L. D" and DC's "The Flash" and "Arrow") and movies (Marvel Cinematic Universe and DC' The Dark Knight Trilogy). However, in the end, I would have to choose Marvel, because Marvel has Spider-Man, my favorite superhero.
Image is #1 the walking dead, nail biters, southern bastards, descender and SAGA. Although out of DC and Marvel I'd have to go DC, the monthly batman series has been amazing start to finish the entire bat family is great and also because prez is fucking awesome.
I like Marvel a little bit more, but I also enjoy DC. I know that is against like all comic fan laws, but I do not care much. Both are good and are really producing some quality movies and mini series on their characters.
I like the Marvel's live action series and films more than the DC ones But the DC Animated universe is better than Marvel's Also Marvel comics take a lot to understand more than DCs, mostly when talking about crossovers.