Comic-wise DC wins.
It has more mature stories, better writing, and a lot more "ingenuity" with it's characters. Marvel falls into "x-men syndrome", where they just flooded their herobase with a bajillion power users. Though DC has horrible PR and pretty awful controversy at times, on a whole it's work is a lot better than marvels. Personally I think watchmen is only rivalled by X-Men, and that's only in certain arcs(because X-men gets pretty fucking lazy later).
While marvels stuff on X-Men and intergalactic stuff is cool, a lot of the earth-bound stories are boring as fuck, as well as a lot of the heroes. I just think DC takes more time and effort to make better characters, while Marvel's best hits are Spiderman and Wolverine.
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Though clearly marvel wins in the movie department. Even if Avengers and all their counterpart movies were mediocre at best, they were a hell of a lot more entertaining than DC's sad attempts at Superman and Green Lantern.
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Personally I like both, and I also like stuff produced by Dark Horse as well.