I’m going to sayyy BOTH FIGHT ME.
It’s a hard question to answer bc there are so many variables on each side. Every line of comics has a different writer/artist combo, and every film/TV adaptation also has a different team, so it’s hard to like the whole umbrella of one side’s work while not liking any of the other.
As far as TV shows go, I’m much inclined to be on the DC side. Young Justice was a fabulous cartoon, the Batman and Justice League cartoons have been reliably entertaining, and I’ve heard/seen good things about the live-action shows like The Flash, Arrow, and Gotham.
With movies, as much as I like the Batman movies, I think the Marvel films are much more true to the comic book roots: they’re bright and flashy and fun (mostly) and they don’t take themselves too seriously. Age of Ultron was a mixed bag, but I would still rather watch that than the new Superman vs. Batman movie, I can tell you that already.
With comic books, IIIII don’t knoooooow ahhhh. I don’t read any of them enough, honestly, to have an informed opinion. As much as I like Fraction’s Hawkeye (Marvel), I haven’t read all of that line, either. I really only know Batman comics and even then, those are hit or miss, lol.
I would claim that DC is darker and grittier than Marvel in general, and in some cases (with movies) that’s probably true, especially since hyper-realism is in vogue thanks to the Christopher Nolan films, but Marvel has its share of hard-hitting stories and dark themes, they just couch them better in snark and comic relief.
At the moment, I’m more inclined to like DC characters, since I’ve grown up with those and they’ve kept me more engaged than the Marvel heroes have, but at the end of the day, I think it’s most useful to find superheroes you like and not worry about which side of the industry they come from.