My first was in about 1990 and it was the colour of magic. I loved the quirky humor and was hooked. I quickly read everything that was published in the diskworld series up to that point. I rediscovered an almost child at christmas anticipation of the next book. I think I've now read all the novels he's done, including the kids stuff. I'd recommend reading them in order as you get a little extra in seeing the character development.
If I need a bit of a lift because I'm having a bad time I can always rely on feeling a bit better for having read on of Pratchetts. My favorite changes and often it becomes the one I'm reading now, some are better than others but I don't think that there is a bad read in the bunch.
My first was Colour of Magic, and then it was any i could get my hands on. I read Strata and Dark Side of the Sun alot now, which is strange considering i hated them at first, but i think everyone who likes his discowlrd series should have a got at them
I read Sourcery first, must have been in the mid 90's, then went back to the start and worked my way through. I actually think Hogfather is a bit disappointing but love most of the rest. My favourite (as judged by most-thumbed-appearance) is Reaper Man.
Equal Rites, I think - in Swedish! The library had a couple of books translated to Swedish and my English was still a bit shaky at the time... However, by the time I'd finished the ones they had in Swedish and I found some more books in English I was totally hooked and wasn't going to let a piddly little thing like being rubbish at reading English stop me. I've never looked back - needless to say I own the entire series now and have lost count of how many times I've read them. I think I can definitely thank TP for a much improved English vocabulary!
Small Gods. Coincidentally a good one to start with as it's a stand-alone one, although I did wonder what Widdershins was... (along with other oddments) Then I had to start from the beginning. They keep getting better and better. My favourite was Thief of Time, then Going Postal, now it's Thud. Still think Small Gods is one of the better ones, but maybe that's just me being sentimemtal.
My first Pratchett was the original edition of The Carpet People. My local library had it from new and, although I don't know the exact date, I assume that I first read it shortly afterward. A few years later the library sold off unwanted stock and I was fortunate enough to buy it for 15p.
I've tried to re-read it as an adult but, frankly, its not a great book. Despite this its probably still my favourite Pratchett as it did so much to shape my reading tastes.
I didn't really like the Tiffany Aching ones, but wintersmith is the more tediouds of the two. My first was The |Wyrd Sisters age 9(8 yrs ago) i know iown all of them-they are fab dab, my friends know not to get me started, as i am obsessed.(i missed the jamboree this year, sob!)
I actually was lucky and started out with the Colour of Magic then The Light Fantastic. It has been wonderful to see how the stories have developed, particularly as they went from what is essentially slapstick to something darker, more defined. As a pure aside, I think my favourite characters, though, are Vimes and Death. Not sure what that says about me!
I thought my first book was pyramids - borrowed from my brother and returned years later when I finally got my own copy - then realised I already had his cat book (very accurate on cat character in my experience). Then read all the discworld paperbacks in order (big fan of the luggage!, also of Death and Granny Weatherwax.), read everything else Pratchett and was soon having to wait for the hard backs. No real favourite book - though I do go back to the early Rincewind and witch books most often.
my first was the hogfather years ago bought it in the hospital cos i was bored then men at arms, the rest is history I have them all as well but the best books are any with the city watch in......pure class!
The Colour of Magic a long time ago was the first - loved it. Loved all the following but was around lords and ladies his books started to change and it was a long time before i settled into the new style (i still read them all though!). Loved Going Postal.
Actually it's the other way round; Widdershins is anti-clockwise, or to be more accurate, anti-sunwise (Northern hemisphere only) and Deosil is clockwise (or sunwise).
I remember that when 'The Colour of Magic' came out all my friends were urging me to read it. Naturally, being a fully-paid up member of the Awkward Squad I resisted their cajolery. I eventually succumbed to 'Equal Rites' a few years later and was immediately hooked. I'm rather glad that I didn't read CoM first - when I did finally get around to it I found it a very inferior book, and it is likely that I would not have continued with the series.