How about Jack Dee, his humour is very sarcastic but his face is the ultimate in deadpan, the audience are in stitches but he has no emotion on his face! Through his show I also discovered Dara O'Brian, and that Ardal O 'Hanlon is much more than dopey Father Dougal on Father Ted. That said I also love Bill Bailey, Dylan Moran and Stephen Colbert, thank you Comedy Central for your free online player!
"What was it Dougal?, collect twelve crisp packets and become a priest!" Makes me laugh every time