I really enjoy the classics. I'm so thankful they've been preserved on Boomerang!
Now, for the list.
Ed, Edd, and Eddy (from the cartoon of the same name.): These guys are hilarious. Especially when they mess up, which is pretty much every episode. Plus, I love the nonsense that comes out of Ed's mouth.
Huey, Louie (spelling?) and Dewey (from Ducktales): These ducks were a great source of mischief in one of Disney's all-time greatest cartoons.
Sonic the Hedgehog: Either by game or cartoon, Sonic the Hedgehog is an icon, and one of my all-time favorites.
Mario: The man, the plumber, the legend. Mario is the icon of videogaming, and he had three cartoons based off of the games.
Those are my top favorites. I have a lot more, but I forgot most of them.