I love T.U.F.F Puppy, Scaredy Squirrel, MAD, The Looney Tunes Show, Kung Fu Panda: Legends of Awesomeness and Dragons: Riders of Berk, to name a few.
Well, I didn't see Scaredy Squirrel (never actually even heard of it, and I'm usually up on these things), an I regrettably (with the annoyed anger of punching a hole in the wall) didn't see How to Train Your Dragon (not for the lack of trying, I was pulled to see Get Him to the Greek instead, but rather loved that film anyway), so I'd probably be lost on that show...
But I totally agree with Kung Fu Panda, T.U.F.F. Puppy, Mad (superior to the live action show in every way), and even Looney Tunes Show... I mean, LTS salvaged 3 of my least favorite Looney Tunes characters, Lola and the Gophers.
I'd also like to add Young Justice, Avengers: Earth's Mightiest Heroes, Super Hero Squad (though it's over
), Batman Brave and the Bold (also over
), Adventure Time, Regular Show, Gumball, and you just can't go wrong with penguins of Madagascar. I LOVE Madagascar, but I like the Penguin spinoff show even more. And, even though I've seen only one episode, the new Green Lantern cartoon pretty much erases the damage done by the movie.
Edit: I'm gonna add Robot and Monster too. Just saw an episode on Nick's clunky player... seriously stupid fun.