Well, I have been a fan of these books since my freshman year of high school. I’m also chronically used to being disappointed by much-hyped films; they never deliver.
Until now.
I knew within the first 5 minutes that I was going to be buying this film as soon as it hits DVD. By the end, I was breathless. The battles are amazing (now I’d dying to see what they do with Helm’s Deep!), the casting impeccable, the acting impressive, the scope simply eye-popping. There’s enough eye candy in the film to sate anyone – lavish sets, impressive subtleties, and an overall epic feel to the whole thing. Jackson works wonders with dramatic camera angles that make Middle Earth feel larger than life.
As for the departures from the book, I can’t think of a single one that I didn’t like. In some cases, they added new depth to the story (such as the expanded business between Saruman and Gandalf, or the replacement of Glorfindel by Arwen). In other cases, they allowed more of the story to be packed into the film without adding to screen time (an example was how in the books you only hear about how Orthanc was a beautiful place while in the movie you get to see both the before and after).
So I was obviously very happy with everything. My only disappointment is having to wait another two years to finish the entire story.
Two friends went with me to see it last night. One is a fellow long-standing Tolkein fan. The other has never read the books and knew nothing of the story. The former has been raving with me all morning about it (he’s a coworker). The latter went down to the store today to buy the books. 
I think I’ll be seeing it another time or two in the theatres, myself. Correction: I know that I will! And for the record, I’m very envious of our friends here at the forum who live in Middle Earth – er, New Zealand. You know who you are! 