DJ QBert (even though he has kind of fallen off the face of the earth). I think modern turntableism sort of hit a wall with him, everybody just sort of sounds like him now. I sort of stopped following this whole scene around... 2002 or so. But I did go to the DMC World in 2008 in London and found that it hadn't evolved too much. The guy is like a fucking wizard though
JRocc - I haven't heard anything he's done recently, but his two Sex Machine mix tapes are awesome, in one he goes from Tom Scott's Today into PR and CL Smooths Troy flawlessly transitioning where the sample kicks in. It is sweet
Cut Chemist - Jurrassic 5's DJ, he did Brain Freeze and Product Placement with DJ Shadow which are both 12 kinds of awesome. They've done some other collaborations as well but I'm not familiar with them. I try to avoid anything DJ Shadow does these days. I treat him sort of like how I treat Weezer. He stopped making music in 2005.
ATrak is another one that I used to like but stopped following. He's sort of like an indie icon these days, I think he played Pitchfork last year.
Of course then there's this awesome shit: