7 years ago, I've started to watch South Park, now it's my favourite show and SP was my first step to get more interested in adult animated shows, and I can say that they've become such a passion to me. To list, I also occasionally watch The Simpsons, Futurama, King of the Hill, Beavis and Butthead, Family Guy and American Dad.
To list apart from them, when I was a little kid, I've loved Hanna-Barbera cartoons so much. My top favourites have gotta be The Flintstones and The Jetsons. Scooby Doo is not bad. Wacky Races is the bomb also. Of course, I don't watch them too often, more like when I just come across on TV... it makes good nostalgia.
During my elemantry school years, Cartoon Network was probably the only reason I sat in front of the TV. Johnny Bravo was my first "crush" on CN. Also Camp Lazlo is pretty good. Ed, Edd n' Eddy has gotta be among the best on that channel. I can say Powerpuff Girls has its moments, a goldie sometimes. Afterwards that period, Regular Show has come up and I can say it's the best of the best I've seen on CN. Oh... also let's not forget Foster's Home for Imaginary Friends, it's at the same level as Regular Show to me, in other words, another best. Almost forgot, Cramp Twins is also a bomb and some of its episodes were really good-scripted and totally absurd.
To be honest, I don't like that Disney crap (not talking about legends like Mickey Mouse, Donald Duck, Goofie. Talking about newer stuff) but Phineas and Ferb, and Kick Buttowski are really good... they were good materials to spend time while sitting at home on boring summer days.
I also enjoy Rocko's Modern Life's cartoonish adultery.
Life with Louie is also one of the best, that can't be forgotten. A really goldie... especially Andy's gibberish when telling his war memories.
The Penguins of Madagascar and Spongebob Squarepants was the way how I begin Saturday mornings for a considerably long time.
Probably, most nostalgic to me is Cedric. Man, I can't forget laying on the couch across the TV about 5 p.m and enjoying the show while eating chips. I was even a huge nut that, at some period I've tried to re-make my own "local" version of Cedric. About a month ago, I've watched some episodes of the series on the Net... was really good, made me have nostalgia.
Also Roboroach, Dr. Dog, Mad Jack the Pirate, Samurai Jack, Ben 10 (only the first installment), What's with Andy?, Tutenstein, Inspector Gadget, Pokemon, Diabolik, Teenage Mutant Ninja Turtles, Arthur can be honorably mentioned.