Which are the best novels by Terry Pratchett and Neil Gaiman?

[nwhyte]

Comments on my not totally effusive post on Good Omens have revealed that my tastes are not the same as everyone's (I know, imagine my surprise, etc). There is of course only one possible way to establish definitively which are the best novels by Terry Pratchett and Neil Gaiman, and that is to conduct a poll. So without further ado: Poll Feel free to justify your choice, or query others', below.