Mark: So what is the reason YOU like Letterman?

;D
My opinions, YMMV:
I also vote Dave. I've been a fan since his (ill-scheduled) morning program, and his NBC late-night program was appointment TV.
He's mailing it in these days, but he's entitled. Even in his current state, his wit runs circles around Leno. Of course, I've always been drawn to acerbic and sarcastic humor. That, and Letterman's appreciation for and curiosity about broadcasting, down to all the funny bits he did in the '80s (the 360-degree show - at the middle break he was upside down). For Ernie Kovacs to have been alive to see David Letterman's star rise ... to have seen the two of them together. Can you imagine the lightning in a bottle had Kovacs guested on Dave's show? The cigar ashes alone.......
Jay Leno is a glorified stand-up comedian WHO SHOUTS THE PUNCHLINES BECAUSE WE'RE TOO STUPID TO GET THE JOKE IF HE DOESN'T DO THAT!!! Jay has his moments, and I've been known to chuckle a time or two during his monologues. But the whole "nice guy/blue-collar/hard-working/denim shirt and cheap tennis shoes" image comes across to me as phony. And I won't get into the, ummmm, "borrowed and repurposed" bits.
I look at Leno and I see a man trying to be a modern-day Bob Hope.
(And thankfully, my phone number is private/unlisted, so Jay can't call me were he to read this)
Those are my two pennies, need change?
--Russell