I have absolutely no idea why I didn't finish watching this back when it first came out. Back then, something (I think it may have been the corny advertising, perhaps) made me look at this adaptation of my favorite Pratchett novel with a harsh eye, and I stopped watching part of the way through. I thought it was badly acted, corny, and not that funny.
Hobbit reference: Never have I been so wrong.
This is a good adaptation, and a great movie - a damn great one - even if, in its miniseries-esque form, it's a bit over 3 hours long. I very much recommend it to anyone who's familiar with Pratchett and/or anyone who can appreciate some British humor.