I don't read comics (except for a few Batman ones once), but from what I've seen, DC has the best movies and games. Marvel has better heroes overall, but DC has better villains, and Batman > any Marvel character.
Marvel's movies are superior to DC's with the exception of the Dark Knight trilogy. Has anyone seen Green Lantern or Superman Retuns or almost any of the Batman movies from the 90's?
Marvel has had some duds (Fantastic 4: Rise of the Silver Surfer, Elektra), but overall produces much better films. I don't read comics much (except for many of the Uncanny X-Men comics), so I'm basing it off the films and characters themselves... Marvel by far. No, they don't have Superman or Batman, DC's two largest, and probably the most popular superheroes from any company, but it all balances out with all the heavyweights that Marvel has right under Superman and Batman.