This is the one question you'll definitely get asked when you're into comic books. For me, I think the answer to this is not really that hard to give. I totally go with Marvel because of several reasons.
Marvel has X-Men, Fantastic Four, Silver Surfer, Deadpool, Punisher, DareDevil, SpiderMan, Hulk, Iron Man, Captain America and all the other Avengers. DC has Batman, Superman, Green Lantern, Flash, Watchmen, Hawkman, Aquaman and then they have a whole bunch other characters that originated from Batman, like Robin, Catwoman etc.
The thing for me is, out of all of the DC characters I'm only interested in Batman, Batgirl and Flash but out of the Marvel ones there's barely anyone I don't like.
Also if we have a look at the movies Marvel is way ahead in my opinion, yeah DC did great with the new Batman series but the Green Lantern movie, Watchmen and Superman Returns all sucked. On Marvel's side there are the Iron Man movies, Fantastic Four, X-Men, Punisher and the old and the new SpiderMan series that has just been relaunched plus The Avengers. Of course they also had some missteps like the DareDevil movie and the first Hulk but overall they definitely have more good movies on their plate than DC has.
I think the people who choose DC over Marvel are Batman and/or Superman fanboys, everyone else should naturally go with Marvel as they have the way better stable of superheroes. Of course that's all just opinion and of course I'm reading and watching stuff from both of them but if I'd have to choose, Marvel would be it.
