Firefly - This show was a work of art. I'm sure I don't need to tell any of you that.
Reaper - This show was great fun, and it ended EXACTLY where it shouldn't have ended.
Stargate Universe - This show started off dead slow and boring in the 1st season and then rapidly became one of the absolute best sci-fi shows ever made in the 2nd season.
Veronica Mars - This show was a work of pure soul. A fiery spirit engulfed in tragedy.
Journeyman - This show started off slow and got canceled at the exact point where you are absolutely addicted and want more. Cancelled right at the point where you like physically NEED to see more.
Better Off Ted - This show was brilliant. Easily one of the funniest things ever put on TV. How this show didn't become a colossal success...I dunno. It's not even like you had to watch a whole episode or understand the characters to appreciate how funny it was.
Spider-Man:TAS - Epic cartoon. I'm about to finish rewatching the whole series. It starts off as easily digestible intros to all the concepts and characters involved and then after a couple of seasons evolved into a sprawling epic. They were never afraid that their audience wouldn't be able to handle the subject matter or follow the plots. They were never afraid to step into the wider Marvel universe when it suited them. They crossed over with X-Men:TAS, he met Iron Man and the Fantastic Four, he worked alongside Daredevil, explored the history and ramifications of Captain America's existence.... Perhaps better than any other cartoon they managed to translate the interwoven complexity of the Marvel universe into a single show.
Spectacular Spider-Man - Much lighter in tone than TAS but nonetheless was quickly becoming a very VERY worthy successor it. Very good show. 2 Seasons simply was NOT enough.
Batman Beyond - THE worthy successor to Batman:TAS. Do I need to say more than that?
Gargoyles - Again, a cartoon not afraid to get grim and serious. Not quite as complex as Spider-Man and a bit more goofy in a couple places, but overall it was an incredibly good show.
The Tick (live action and animated) - It's awesome in EXACTLY the same way The Venture Bros. is awesome, which should be no surprise since Jackson Publick is/was heavily involved in both. You can NEVER have enough of The Venture Bros.(scientific fact).
As someone who loves X-Men:TAS, Batman:TAS, Spider-Man:TAS, X-Men:Evolution, Batman Beyond, Spectacular Spider-Man, Justice League, Justice League Unlimited, Young Justice, etc etc etc (you know, the REALLY great superhero cartoons), I can't for the life of me understand why so many people in this thread seem to like Wolverine And The X-Men enough to name it as a show that they want back.... That show bores the hell out of me in comparison. I have the entire series and simply CAN'T make myself watch the whole thing.