The Lord of the Rings Trilogy. I was fairly apprehensive before the first film came out. Other than Heavenly Creatures (great film, by the way), most of Jackson's work was a little, well, dark, odd, bloody, creepy, and just plain whacked (and really, Heavenly Creatures could be called all those things too). This was the guy the film studio trusted to turn this genre-creating classic into cinematic genius? But I think the whole creative team did a great job of creating the movies.
Pretty much sums up how I feel about the Orcs. [Source]
When you look at the breadth and scope of the books, I would be hard pressed to think of anyone who could have done it better. That's not to say that I have no issues with them (ending the second movie with the Battle of Helm's Deep left waaaaaaay too much material for the third film--the battle is about halfway through the second book--which left the pacing in the third film feeling rushed and a few subplots barely developed, although the extended DVD did a good job of fixing that issue) but when the good parts are soooo good, I'm willing to give a pass to my few issues.