OK who would you cast in a Discworld movie?

Pick your faveorite book and list who would play whome

This is what I'd go for

Book: Carpe Jugulum
Cast:

The Count : John Clease
King Verence: Eddie Izzard
Big Aggies Man: Billy Conoly
Magrat Garlic: Camron Diaz


I'll add more as I think of um