I was just going to post a thread in this very vein.

Its definately a toss-up between Peter Cook, Eddie Izzard, Ricky Gervais and Chris Morris.

on mock the week

Izzard, back in Dress To Kill/Definite Article days.
I quite like Demetri Martin.

stewart lee as has already been mentioned.
marcus brigstocke is pretty good too.
and i like russel howards stand up.
and the old frank skinner stuff.

He's by far the best stand up of his generation, and his more theatrical stuff is excellent as well. Stewart Lee is probably the only one that comes close, but even then he doesn't come that close.

obvs

he's pretty funny but that's all I get from him.