Try search in google for "terry pratchett book list" - and you get a really cool looking 'list' of books above all the regular search-engine marketing and results. It looks pretty cool:
Give it a try in google.
OK, so here is my list (in approximate order of publishing or reading) ones in RED have been read, green ones are still to be eaten.
The Colour of Magic
Truckers
Diggers
Wings
The Carpet People
The Light Fantastic
Equal Rites
Mort
Sourcery
Wyrd Sisters
Guards! Guards!
Pyramids
Eric
Moving Pictures
Reaper Man
Witches Abroad
Lords and Ladies
Small Gods
Men at Arms
Interesting Times
Soul Music
Maskerade
Feet of Clay
Hogfather
Jingo
Carpe Jugulum
The Last Continent
The Fifth Elephant
The Truth
The Amazing Maurice and his Educated Rodents
The Last Hero
Thief of Time
Night Watch
Monstrous Regiment
The Wee Free Men
A Hat Full of Sky
Going Postal
Thud!
Wintersmith
Making Money
Unseen Academicals
I Shall Wear Midnight
Snuff
Dodger