I know this starts out wrong, but please bear (bare) with me ;)
I've only read the first Terry Pratchett's novel, Color of Magic, and quite frankly, I read the first chapter or so and let it sit for a 1/2 to 3/4 of a year. Once I picked it up again, however, the pages flew by and I finished it quite promptly. It was an extremely colorfull depiction of an alternate universe that had very close ties to our own. Of course, being fantasy, or literal fantasy, it resembles more of the english speaking folklore and mythology, than any actual historical events. Now take all that, give it a, stir, a chop or two, infuse some octarine, and you have Discworld.
This was the information I had going into viewing this wonderful film. To say the least, it was a wonderful show that entertained me to the core. Extremely well done, the focus here is on the actual work done by Mr. Prachett. It doesn't have the Hollywood abundant budget, but more than makes do with the resources that were available to it. Vadim Jean (adaption and director) has used the gift of ingenuity to create a truly spectacular and heart warming family holiday masterpiece. I was spell-bound and in awe of this great work of art.
If you're looking for a magical slaughter-fest, this isn't it (although the death count is higher than most movies). If you're looking for a story that has been dramtically reproduced with loving care about us as a whole, with a definately UK slant at humor, this is a show for you (heck, it even attracted the attention of my 15 year old boy to stop and watch).
So in summary, I had rented it, but as soon as it is available I'll be purchasing a copy of this to view each holiday season. There is just something about it that calls to you and make you think Hogswatch, er I mean Christmas ;)