*disclaimer: Obviously, music quality is a thing of pure opinion.*
One thing I miss from Everquest, especially the planes of power, is the music. A lot of the tracks were at least up to par, and made a lot of sense being where they were. For an example, you can youtube up bastion of thunder, which is a tower in the plane of storms. It really sounds like a stormy symphony. It also sounds good!
The main thing I have missed ever since I started DDO has been GOOD MUSIC. My current up-to-date list of quests that I enjoy more because the music is good is as follows:
-Finding the Path
-Sinister Storage
-Spinner of Shadows
I would love to see a guy assigned to go through the old game and put in some thematic music. Yeah, many people listen to their own, or keep any music off anyway, but I appreciate game music that tries to get me more immersed in where ever I currently am.
And really, even just a decent sewer theme would cover like a quarter of the game.
Raids, I would really wish for a unique theme for each raid boss.
Good music themes in games make things feel so much bigger. I know I wouldn't have been so awed by Magus from Chrono Trigger if his music theme wasn't also freakin amazing.