Carlin will always be great
Some of my faves are Dave Attell, Louis CK, Nick Dipaolo and the late / great Sam Kinison deserves a mention as well.
Let's get some examples going (consider everything to be NSFW):
Kinison - not his best stuff. But seriously, once you get past the screaming, I think it's good stuff.
Louis CK
Attell - try to find Skanks for the Memories...way funnier than his newer stuff
Nick Di Paolo way more hostile than usual haha