I love(and have loved) a lot of shows! Sonic the Hedgehog(a.k.a. SatAM..BEST SONIC SHOW), Gravity Falls, Adventure Time, Bob's Burgers, Archer, Venture Bros., Courage the Cowardly Dog, Batman: The Animated Series, etc. It's hard to pick JUST one!
It's Always Sunny In Philadelphia is my all time favourite show...
Walking Dead, The X-Files, The Wire.. and basically a lot of the shows Brad mentioned up there. I'm also really enjoying How To Get Away With Murder
I can't say I watch much TV, but out of the shows I've watched, Rome was my favourite before it went off the air. It was kind of like GoT set in Roman times, and I loved it.
Excluding anime (since there's too many) I'd have to say Avatar: The Last Airbender. I know it's pretty much like an anime, but it's not under that category so I choose it. Legend of Korra is also a really good show. It can't beat the original though.
Big Brother. It's so funny. And sometimes there can be smart people who actually do things correctly instead of "looking for a soulmate" and all that sappy junk.