Either Ultimate Spiderman or Legend of Korra (ATLA aswell)
all time i'd have to say Danny Phantom
side ones would be
Fosters home for Imaginary Friends, My Little Pony: Friendship is Magic, American Dragon: Jake Long, Sabrina the Teenage Witch (yes the Saturday morning cartoon), allot of old Nickelodeon shows like CatDog, Angry Beaver, AHHH! Real Monsters, Hey Arnold, Ren & Stimpy, Rugrats, and yeah allot
Carry on my Wayward Son, there'll be peace when you are done. Lay your weary head to rest. Don't you cry no more...