That's a tough question, in part because I don't watch a lot of the cartoons.
A lot of the cartoon characters I've seen haven't been particularly revamped, but then the ultimate books I don't read (USM + UXM) aren't much of a re-vamp, either. So, on the main, if the question is strictly one of re-imagining characters, neither one is doing a thorough job.
Ultimates and Ultimates 2, though, present a DEFINTE re-creation of the "Avengers." Ultimate FF has been heavily "tweaked" ... and Iron man ... well, let's not talk about iron man.
The DC cartoons I've seen are just really good (usually) stories using the same (or at least very, very similar) characters from the books. I don't see many changes, not that you need to make changes to make something good.
But the question was who is better at revamping.
Ultimates win it on a technicality.