Russell Brandt was great in Forgetting Sarah Marshall and his hour-special was okay. I'll need to see more of him.
Christopher Titus has such a great voice for his dark absurd style; I've loved all of his specials I've seen, so his show will be something to watch in the future too.
Mike Birbiglia's a fun story-teller with casual appeal to boot. "What I Should Have Said Was Nothing" is a special worth watching, especially before Bush-jokes become past their prime (even further past, anyway). I'll need to see "Sleepwalk With Me" sometime.
Brian Posehn was best on the Sarah Silverman Program. The one Roast he was in (his only one -- maybe Bob Saget's?) where he joked about replacing Lisa Lampanelli was a good appearance too.
Jeff Dunham's weird to me; I didn't care for him at first, then he grew on me, and NOW it's back to borderline-apathy. Walter and Achmed are probably my favorite puppets, but Dunham can actually be good without them when he opens a show too. It brings me joy to talk about how bad his show on Comedy Central was though; his series-opener broke CC-records with a 7.9-premiere, yet by the end of its only season it was getting ratings as low as 1.3. Stick to stand-up!
Speaking of sticking to stand-up, Carlos Mencia wouldn't be nearly as bad if it wasn't for Mind of Mencia. Many of his specials are good, including his Comedy Central Presents-episode before he really blew up...but his show, goddamn. His show was a vehicle for three things each episode: slam Bush predictably, sing songs terribly, and yell "Dee dee dee" often. It was good to see him return to stand-up recently though, even if it was one of his weaker specials.
Marc Maron is somebody I'll give another chance, but -- like Bill Mahr -- I don't care for his angle of political humor so much. Jon Stewart and Stephen Colbert have done such a great job claiming that corner of comedy, and even then I'll take familiar correspondents from the Daily Show like Lewis Black/John Oliver/Wyatt Cenac/Rob Riggle over Maron/Mahr. Hopefully "This Has To Be Funny" turns me around on Maron.
Kathy Griffon's hard to beat on jokes of gossip and fame. She did a good job hosting the Roast of Joan Rivers, too.
George Lopez's sitcom was decent, but I don't care for his specials and dislike his talk show.
Joe Rogan tries to be a loud comedian too often, but he can get laughs and has interesting points. I still know him best for Fear Factor, which isn't exactly comedy...but I won't hold it again him!
I couldn't get into Bill Burrs much, though there are some specials of his I haven't seen yet too. I'll keep giving him a chance, I guess. He was funny as an announcer on Chappelle Show, at least.
Dave Attell's one of the best dirty-comedians today, mostly because of how he ridicules himself along the way. He was a favorite of mine growing up because his one-liners hit fast.
Don't know Ray William Johnson or Michael McIntyre.
--
http://img812.imageshack.us/img812/3492/eponaharr.jpg
Nominate SuperNiceDog's Guru-choice, then Epona.