I used to go see a ton of stand-up back in the day (20y ago), it was an exciting time for comedy. It's cooled off considerably since then, and the whole comedy world seems to be in hibernation for the long haul, sadly. Although maybe if I atually got my ass back out to the clubs, it would be a different story.
Anyway, he's a completely different character now sadly (it is what it is) but for my money Adam Carolla, at his peak (early 2ks Loveline years) was indomitable. I still go back and listen to some of those old shows and crack up, no one was quicker (or angrier!) Otherwise, I'd say Louis is the enduring GOAT. Also has fallen off since his peak, but he's still got it. I'll go back and watch his Fox show and still get as much of a kick out of it as ever, just brilliant work.