For me, Disney wins without question. I grew up on Ducktales and Chip and Dale's Rescue Rangers. As much as Loonietoons was also a big part of my youth, when I look back and think of that type of cartoon, it's Disney characters I see in my mind.
This is such an excruciatingly difficult question. I think for me, when it comes to Disney's classic movies, they come tops. However, if you are referring to the shorts, such as Mickey Mouse/Donald Duck/Goofy cartoons, then I prefer Warner Brothers and their Looney Tunes characters.
For me it's Warner Bros, for Bugs Bunny and the Animaniacs. The only Disney cartoon I really liked (except when I was really little and watched The Wonderful World of Disney religiously every week) was Talespin. I wanted a sea plane really badly. Kids are funny like that.