I would recommend Japser Fforde. His Nursery Crimes and his Thursday Next series are great. They are not to everyone's taste, but if you like them you will LOVE them.
To give you an idea of their style, this is an excerpt from Wiki on his writing,
Fforde's books are noted for their profusion of literary allusions and wordplay, tightly scripted plots, and playfulness with the conventions of traditional genres. His works usually contain elements of metafiction, parody, and fantasy.
The Thursday Next series is especially good, with Thursday herself a terrifically written and thoroughly substantial central character. They are clever and witty books.
I would second the Terry Pratchett Discworld, books too, here's a handy wiki guide.