Powerpuff Girls, hands down.

jkatz wrote :

Without Hanna Barbera, there would be no Johnny Quest. Without Johnny Quest, there would be no Venture Bros (and the rest of Adult Swim would probably  be very different). I'm gonna go with Johnny Quest.
-end quote

I would go with Space Ghost since Coast to Coast is the granddaddy of Adult Swim.

Ahh... Space Ghost...

Zorak was funny for an evil guy.

Hokey Wolf. So much like Yogi, but in wolf's clothing.