If you like completely silly humour, 'The Pirates....' books by Gideon Defoe are well worth a read. They're totally nutty, and you'll love them or hate them.
Phil
Check out Alan Partridge's 'autobiography', as others have mentioned.
Genuinely laugh out loud from cover to cover.
"Thoughts tumbled through my head like trainers in a washing machine"
Any of the Wilt series and defo Blott on the Landscape.
If you are looking at Tom Sharpes books I would really recommend the two about the South African police - Indecent Exposure and Riotous Assembly. Two of the funniest books I have ever read.