Probably my all time favourite comedian is Eddie Izzard. He just makes such sophisticated jokes, and he can actually do dramatic roles pretty well too (see the movie Valkyrie for a good example).
Then there's the late Robin Williams who did a lot of impressions, and has always made me laugh. Just like Izzard, he could go from comedy to drama extremely well, which is why he will always be an inspiration to me.
I like Hugh Dennis and Milton Jones, both of which are able to do good deadpan performances.
There's Steve Coogan and Rob Brydon, whose banter is just top notch. Other comedy duos that I've found funny are Mitchell and Webb, Armstrong and Miller, Ant and Dec, and of course the legendary Laurel and Hardy. Their slapstick comedy is some of the funniest I've ever seen, great inspiration.
Though they're not exactly comedians, Jeremy Clarkson, Richard Hammond and James May are hilarious when they're together. I wish they were still together on Top Gear, sadly they're not, but they've got a show on Amazon Prime called The Grand Tour which will be out soon, so I will hopefully be catching that soon.
Last, the group known as The Tenderloins, which others may know as the Impractical Jokers. Sal Vulcano, Joe Gatto, Brian Quinn and James Murray, all four of them are comedy geniuses. I love what they do and I hope they never change.
There's so many more but I can't name them all right now. I'm a sucker for good comedy.