Captain Hero from Drawn Together. He's chavuanistic, bisexual and incredibly offensive, yet he fights for truth and justice. You gotta love him.
Ed from Ed, Edd n' Eddy. His non-sequiters and random references are great.
Bubbles from The Powerpuff Girls. I dunno why, she just is. I guess because she's not a know it all (Blossom) or a jerk (Buttercup).
The Red Guy from Cow and Chicken. A butt nakes devil rolling around crossdressing and harrassing little kids is just hilarious to watch.
Ranting Swede from Sheep in the Big City. He rants about everything.
Sokka from Avatar: The Last Airbender. Poor guy is used as a punching bag and gets absolutely no respect.
Johnny Bravo from Johnny Bravo. Unfortunetly, he became incredibley dumb after the first 2 seasons.
Anyone from Family Guy.
Roger from American Dad. Everything he says = Comedy gold.
The Flash from Justice League Unlimited. Same reason as Roger.