Animaniacs sucks, with the exception of Pinky and the Brain. That's why they got their own show.
Tiny Toons was awesome, as was Freakazoid and the short-lived Earthworm Jim cartoon.
Going way back into the vault, I was, and still am a huge fan of the Mario cartoon series'. The original was great, especially with the Zelda cartoon they'd throw in there every friday. However, the best of the bunch was definitely the Super Mario Bros. 3 cartoon. I only ever saw one episode of the Super Mario World show, and I must have seen that single episode about six times.