I think I like surreal, nonsensical humour the best - humour that forces together unrelated ideas to create something new. Examples would be: The Goon Show, Tex Avery Cartoons, Spike Millgan's "Q" Series, Monty Python (of course), The Young Ones, Vic Reeves and Bob Mortimer, Father Ted, Eddie Izzard and The Mighty Boosh.
I prefer humour that is quite warm-hearted. I don't get the appeal of shock comedians like Bill Hicks and George Carlin - Firstly, I'm not actually shocked by them and second, I'm often already in agreement with the point they are putting across. They just seem too much like bullies to be.
I can appreciate some dark and gruesome humour (like The League of Gentlemen).
I can't stand those teenage comedies where everyone is out to get laid (American Pie and Porkies) - they just remind me how awful that period of my life was.
Finally, as a Brit raised on a diet of Carry On movies, Benny Hill and Are You Being Served, I just can't say "no" to a nice big juicy double entendre.