Wyrd Sisters is about three witches in the Discworld - it's the sixth or seventh book in the series but it's the one that introduces the witch characters so I thought I'd start with this one rather than the real first one. The story itself isn't spectacular or anything, but Pratchett's writing truly is fantastic. He uses so many references, so many joeks - I'm sure that I missed half of them and was still amused. It's intelligent writing and I like that.
Everything I read these days gets 4 stars and I'm waiting for a 5-star book. I was hesitating with Wyrd Sisters so it gets 4.5. :-)