Here's a documentry that was on the BBC the other night about Bill Hicks. Bill Hicks Doc.
As for your list there's a lot on there I don't know I guess they're not too big here in the UK. Bill Hicks is my particular favourite, but John Stuart, George Carlin and Richard Pryor all do some great stuff. As for Dennis Leeary, yes he may have ripped off Bill Hicks big style but No Cure For Cancer still makes me laugh.
I didn't know Jon Stewart did stand-up... I'll have to look into that.
Agreed on Lewis Black, Patton Oswalt, and Bill Hicks... I think Ron White and Daniel Tosh are better than mediocre... but everything else, I pretty much agree with. There are a lot on here I've never heard of. I should fix that.
For fuck's sake, where is Stanhope? If the rest of the comedians in the world died and Stanhope survived, comedy would still be rich and vibrant. Rasheed Thurmond, Ian Edwards and Russell Peters also worth it.
However, what this list is really missing is British comedians. Don't understand why you like our news sites but not our comedy. Our comedians are bigger and better than yours, bigger in that stand-up comedy is more popular here and better in that the ones who do get famous aren't idiots like Cook.
Ricky Gervais, Ross Noble, Bill Bailey, Johnny Vegas, Jack Dee, Eddie Izzard, Irish legends Dylan Moran and Dara O Briain, the list goes on ...