Best IMO is anything from the 90s. All the stuff I used to watch on Nick and Cartoon Network.
Ren and Stimpy, CatDog, Hey Arnold, Ahh Real Monsters, Rugrats, Rocko's Modern Life, The Wild Thonberries, Dexter's Lab, Courage the Cowardly Dog, Powerpuff Girls, Johnny Bravo, I Am Weasel, Ed Edd n Eddy...
Disney Channel cartoons. The spin offs from the films, like Aladdin, The Little Mermaid, Timon and Pumbaa, Tail Spin.
Art Attack. Rosie and Jim. The dreaded Teletubbies.
Also, 80s shows like XMEN and He Man, ReBoot.
The classics: Scooby Doo and all the HannaBarbara stuff. The Simpsons and Futurama.
Modern stuff we like: Sanjay and Craig, SpongeBob SquarePants, Adventure Time, Star Wars.
Not a fan of CBeebies or CBBC. Find most of their programmes twee and patronising. We liked Nev the Bear though.
Sorry, that turned into a nostalgia information dump.