Good grief! Where does one start?
Should comic actors be included? (Tony Hancock, for example?).
Sketch performers? (Eric Morecambe? Ronnie Barker? John Cleese? John Bird? John Fortune?)
Comedians who don't need any scripts at all? (Linda Smith?)
People who can be incredibly witty and, at times, outrageously funny, but who wouldn't think of themselves as 'comedians'? (Alan Coren?)
Brilliant stand-up performers (Joan Rivers?)
Those who combine stand-up with sketches? (Dave Allen?)
Those who paint scenes in your mind? (Al Reed? Bob Newhart? Victor Borge?)
Those who work with both words and music? (Victoria Wood? Dillie Keane? Tim Minchin?)
I can't really chose out of that lot but, simply because I've seen her performing live (and loved every minute of it), I'll go for the wonderful Dillie Keane: