Ah, i have too many favourites to mention. However, the first one i read was The Hogfather.
Carrot is one of the best characters, with his single sided view on the world, and his friendship, or at least respect that he gets unasked, with the whole city.
Some of the rarer characters in the book, that i really like, are the Nac-Mac Feegle clan( correct my spelling) Wee Mad Arthur, Cohen and Death.

Har har har!!! Grondy fancies Grany Weatherwax! Who would say? I got a picture of her Grondy, on the map of Lancre. She really is old! Pretty thin too. And Nanny!! She really looks like a gummy walnut! (or perhaps a sultana)
Thats C.M.O.T. Dibbler your thinking about Grondy. Yeah...those sausages are LETHAL!!

I love lots of characters in Discworld. They are all so bizarre in one way or another.

Dibbler, Carrot, Vimes, Vetinari, DEATH, WHO ONLY SPEAKS IN CAPITALS, the funny little guy who sweeps the temple, many more, not forgetting 'The Luggage'.

I wasn't quite as impressed with Going Postal as I was with the previous books but I still enjoyed it.

I thought Going Postal was not as good as many others, but much better than Monstrous Regiment, which preceded it. Actually, most of MR was okay… I just didn’t feel that the end was… ready?... believable. I always feel weird saying that, because I mostly feel that anything can happen in Discworld. But I think that only pertains to the world. The people are ordinary, for the most part… even more ordinary than you would expect people who live in a place like Discworld (or who are characters in a fantasy) to be, most of the time. Especially in this book, at least the main character. And I think the end, the part I didn’t believe, was a people thing… SEMI-SPOILER (I tried to be as discreet as possible. Those who have read the book should know what I mean)… I just couldn’t believe that that many people could get away with that with only one person knowing, or that they could get to be so important and still let that be forbidden. Especially if people mostly follow the Duchess…. I don’t think she would disapprove, even if whichever god does… (was it Nuggan? I know he forbids weird things… or was it the Duchess that disapproved anyway, or not a religion thing at all? I can’t remember, and I don’t really care to read the book again…) END OF SEMI-SPOILER
The Watch is better, anyway. Much deeper characters… probably the deepest books are all the Watch after the first one, Witches Abroad, and Reaper Man…

I believe Thud! is about the sound of a club hitting someone’s head and has to do with the Battle at Koom Valley (the only one known to history where each side ambushed the other) and the Watch (yay!). And I like Granny Weatherwax! I said I really liked Witches Abroad! (well, actually I just said it was deep… but I do really like it.) I think that is the one that shows her off the best. Lords and Ladies is more about Magrat, and Maskerade and Carpe Jugulum are more about Agnes/Perdita. Really, after WA, the best sense of her comes from the Tiffany Aching books (Wee Free Men and A Hat Full of Sky). By the way, does anyone else think Tiffany seems too old for ten or twelve or whatever she’s supposed to be? Or is it just that I can’t remember being 12 accurately (it wasn’t that long ago, either…)?

I've read almost all of the Discworld books. I've enjoyed some more than others. The first Granny Weatherwax book I read was Equal Rites. She has grown on me since then, esecially after readying Witches Abroad, Lords and Ladies, and Maskerade. Granny is now one of my favorite characters. I epsecally liked the bit near the end of Makerade where Granny says (sorry, I don't remember the exact quote) something about Black Aliss being the meanest nastiest witch there ever was, and about being able to spit in her eye and kick her a**.  You have to love Granny.

I have never read Pratchett, Kafria. If I was to read one book, which one would you suggest?  

I LOVE Good Omens, Terry Pratchett and Neil Gaiman, so, so much good......

Otherwise my favorites are:

Going Postal

Wee Free Men series

Maskerade.