1. Recess gang
  2. Hey Arnold neighborhood
  3. Team Rocket Power
  4. Rugrats babies
  5. Powder Puff girls
  6. Animaniacs
  7. Bonus: All That crew
    Not a cartoon but they count!
  8. Doug and company in Bluffington
    Suggested by   @lizabeth
  9. Aaahh!!! Real Monsters
    Suggested by   @lizabeth
  10. Rocko's friends helping him face the modern world.
    Suggested by   @lizabeth
  11. The Tiny Toons, Acme University's finest
    They're all a little looney
    Suggested by   @TheSteve
  12. Arthur's friends
    3rd grade never looked so cool!
    Suggested by   @bware427