Jonathan

Loved this book - can't think why it took me so long to get around to it. Maybe because I was reading all of Pratchett's... (the two collaborated on the brilliant Good Omens - read that if you haven't)

If I had to sum this up I'd say an adult ‘His Dark Materials' except far better, much less preachy (i.e. not at all) and very funny. It's not laugh out loud funny, like Pratchett or Douglas Adams (I'd say Gaiman is self-consciously writing in an Adamsian style) but wry chuckles all through.

I listened to the author reading this on my commute and I really recommend it - he delivers a dry, well acted performance and, being the author, knows exactly how he wants things to sound.

Good book, and now I'm going to have a bit of a Gaiman binge, I think...

I really didn't enjoy this, which is why it took so long for me to finish - nowhere near as good as The City of Death, it tries to hard to be funny and falls far short. The last quarter of the book is better than the rest, but it's a low bar.
The end of the book contains some interesting information about the Douglas Adams archive in Cambridge, though, and the bits that weren't in the TV version show Adams's creative process in an interesting light.

I gave this only three stars because, while it's a great book, compared with what comes later it's nowhere near the heights the series reaches. If you're new to Discworld, I'd suggest not starting here (other reviewers offer their suggestions) but coming back to it later to see how it all started.
I reread it as I'm trying to reread the series in order, just as I did originally beginning in around 1990. I can't recommend the Discworld novels highly enough, even the least good (like this first entry) are very funny but the best are philosophical masterpieces and comically brilliant. The Colour of Magic suffers from trying to cram too many ideas into a short book - later efforts would have taken just one or two and developed them. It's also more a clear parody of a certain genre of novel, with gods and heroes at the periphery while minor-ish characters like Death would later go on to dominate.
Rereading it now, it feels odd that it was ever published but as you progress through the series you'll be glad it was.