Anything set in Discworld is marvellous. And the beauty of it is that you really don't have to read them in any sort of order (it makes a little more sense if you do, but most of them are fairly self contained). I recommend the stuff focussed on Granny Weatherwax and the witches, or anything in which Death plays a major role. (I think Soul Music and Moving Pictures are a couple of those...) *nods sagely*