Good Omens by Terry Pratchett
(and in fact many other of his books too)
Fried Green Tomatoes at the WhistleStop Café by Fannie Flagg - the bit where she smashes the young girls' car in the carpark. Can't remember any specifics from Daisy Fay to say that made me laugh.
Several of Georgette Heyer's books - not just you, Takver - but especially Frederica, Arabella, The Grand Sophy, and some of the detective ones.
Bill Bryson but I am to admit I can't remember which
The Secret Diary of Adrian Mole made me laugh when I was younger; Bridget Jones' Diary when I was older.
Something by Michael Palin but cannot for the life of me remember what - but I was nearly bursting with trying not to laugh out loud on the plane!
PG Wodehouse - usually raises a smile and sometimes a snigger
Marian Keyes - Further Under the Duvet (second of her autobiog/article books) - her description of the Irish Embassy in London when trying to get a new passport is brilliant!