Always George Carlin. His old works if you prefer a less visceral / political approach. He plays around a lot with humor involving the English language.
Jim Gaffigan.
Ron White.
John Caparulo (Meet Cap).
Will E Robo is a lesser known comic I used to enjoy. Quality posts featuring him are pretty much gone from the internet at this point though.
Robin Williams.
Bob Saget (believe it or not).
Steven Wright is the king of one liners.
Patton Oswalt is alright.
Hannibul Buress is alright.
One of my favorite stand ups who turned out to be a sex offender.
I'm not very familiar with British comics. The only one I can think of is Eddie Izzard, who I love. I think Richard Ayoade, Ricky gervais, and Russell Brand have done some routines in the past, but they're not much known for stand up.
Not traditional stand-up, but James Veitch's Ted Talks are great.