Comedians from the seventies up I've enjoyed: Garry Shandling, Bill Maher, Sam Kinison, Richard Jeni...
I agree with Kerry about the late Dennis Wolfberg and the off-beat Taylor Negron.
I like most of the Blue Collar comics: Jeff Foxworthy, Bill Engeval, and especially Ron White...Don't like Larry the Cable Guy.
I think many comics like Jay Leno and Drew Carey were more interesting and cutting edge before they became mainstream TV. Seinfeld is funny.
David Letterman still cracks me up, though he doesn't do much stand-up anymore.
Some smaller time ones who I've found very funny: Patton Oswald and Dana Gould.
I've found very few women comics funny: Joan Rivers in her heyday could knock out the zingers. Sandra Bernhardt can get me going and stop me just as fast, wish she'd stick to the comedy and leave the singing alone.
Some interesting blasts from the past...all probably started before the 70's but worked well into them...Frank Gorshin, John Byner, Jackie Vernon, Jackie Leonard, and the always wonderfully bizarre Pete Barbuti...who was kind of a comedian's comedian. He'd always kill the guys in the band when he appeared on Carson. A sample of Barbuti's humour: "A guy digs up Bach's grave and lifts the lid. Bach shouts from the coffin: 'Close that! I'm de-composing!' "
Henny Youngman and Rodney Dangerfield were always great with one-liners.
Don Rickles, who is handled by my business manager, and so who I see every now and then, still makes it work just on pure rim-shot rhythm...even when the jokes aren't funny.
Cos was great growing up as was Newhart and my pal Shelley Berman. Having worked with Shelley, I can tell you he is not only one of the funniest people I've ever met, he's also one of the brightest. You could just sit with him in a diner and he could have you laughing so hard, you'd be crying. He also did one of the funniest after-show speeches I've ever heard...improvised and different every night.
Though he wasn't a stand-up, the funniest comedy album I've ever heard is still Stan Freberg Discovers America.