They are releasing the full LOTR scores on CD! (Insert loud, girly squealing here.) The Fellowship CD set has been out for a while, and the Towers set is scheduled to come out on the 7th.
I believe every movie with a decent soundtrack should do this. I believe Moulin Rouge should still do this, they've made two CDs and still haven't put on everything I want them to put on. (How I have managed to live my life this long without every single note of music from Ewan McGregor's lips on that film, I just don't know.)
Anyway, my real explanation for LOTR is the fact that the first movie has a great score. I know it minute by minute. You play me some of the music, I can tell you what scene it's from. That's partly because when I moved in to my dorm it was the only DVD I had, and I had no television. When I bought the computer it pandered to my greatest love (it came with a copy of Fellowship), and included with it what has grown to be one of my greatest loves (The Sims). Pretty much all I did in my spare time from August to Christmas was watch the DVD and play Sims.
So, that CD I just plain love. The other two movies have nestled in to my heart really because of one thing. The hardanger fiddle Rohan theme. It doesn't much sound like a hardanger is supposed to (because I think a hardanger is Norway's answer to the nyckleharpa), but it also sounds nothing like a violin. I can't recreate the sound, and believe me, I've tried. Even if I could match pitch...
On the subject of obscure instruments, a nyckleharpa is Swedish. It's distantly related to the hurdy gurdy, which is possibly French or Italian. The hurdy gurdy is featured in Donovan's song Hurdy Gurdy Man for which George Harrison wrote one of the (seldom heard) verses. George Harrison was a member of The Beatles, and that is how The Beatles and The Lord of the Rings are six degrees of seperation from each other (or is that only five?), unless you're counting the fact that the music of both was recorded at Abbey Road Studios.
At least, in my ridiculous passions, I am thorough and consistant.