Breaking Bad - Best Tv Series I've ever seen
The Big Bang Theory
How I Met Your Mother
I also liked Startgate SG1 and Stargate Atlantis
If you don't object to anime, try Death Note, it's really good.
On my to see list:
Sopranos, The Wire, Homeland, Boardwalk Empire
Nobody beats Vitas Gerulaitis 17 times in a row. - Vitas Gerulaitis, on finally beating Jimmy Connors