Oh yes the books with the witches are awesome... I like the ones with Vimes and Death. Death is the best
Monster Command was good, Small Gods is awesome, totally changed my view about religion
, Guards Guards was one of the first I read, Sisters in the Business (if that's how it should be translated in English) was the best from all the witches' books... I really liked that part where Gita starts shouting "He's the murderer!", when they were at the theater, I laughed so hard
... no, I gotta say, everything is so... well-written in these books, every part is soo... awesome.
Well, there are many other good authors like Robert Sheckley, Untouched by Human hands is... well, awesome. It consists of short stories... Sheckley writes... very short stories, you gotta read that book sometime.
About Prattchet, I've always wanted to read Where's my cow? but I can't find it... have you read it?