Was just going to start this thread!!
I just found out that you could do this last night (and was up until 2 adding things)
For Towns:
I use selected tracks by Danny Elfman. Some of the "nicer" ones (from Edward Scissorhands, Willie Wonka, Big Fish, and Sleepy Hollow to be exact)
I also use the "Concerning Hobbits" track from LOTR
For Dungeons:
More Danny Elfman.. but this time from Batman Returns, Willie Wonka (think the boat ride, it's PRICELESS when in a ruin filled with goblins ), and the creepy stuff from Sleepy Hollow.
i also use a track or two from the movie "The Rock", and some LOTR stuff like "Shelob's Lair" from Return of the king and Treebeard's theme.
... I know there's more... I use tons of cave stuff.
For Battles:
A lot of the score of "Matrix Reloaded", some tracks from Kill Bill, A wonderful track from Beetlegeuse, and a uh.. track or two from the Anime "Bleach"
For Exploring:
Here's where Howard Shore and LOTR really kicks in.. lots of Rohan themed stuff as well as the fellowship themed pieces.
Also some stuff from Afro Celt Sound System (band), The Rock, and assorted Danny Elfman (Yes, I know I love him too much )
The stuff I'm really trying to find more suitable music for is while in town.
Oh and I still have all the Vanilla music running.. It meshes pretty well, actually!
EDIT: Whoguru, where do you find that remix of the theme? I'd like to give it a listen!