Animaniacs
Rocko's Modern Life
He-Man
Biker Mice From Mars
Earthworm Jim
The Attack of the Killer Tomatoes
Inspector Gadget
Doug
Angry Beavers
Dexter's Lab
Rugrats
Thundercats
X-Men
Samurai Jack
Powerpuff Girls
The Grim Adventures of Billy and Mandy

But yeah blatantly the absolute best cartoons ever are Animaniacs and the stuff that span off from it (Specifically Freakazoid and Pinky and the Brain).

Though god damn I do love Samurai Jack.