If you like orchestral or just generally well-written music, buy the cds to either the Slayers series or OnePiece.
I have many from both. Have to say for Slayers that the TV, 3 SoundBible, and 2 Try CDs are all good. I also have the movie cds and like 'the motion picture' S one the best. Try to stay away from the major large-case cds as they're usually all spoken songs (in engrish and japanese) and I don't find them nearly as mood-swinging as the written music ones (which have spoken songs through them, but it's a good mix and the spoken stuff isn't overwhelming).
All the slayers CDs have a character monologue infront of it. Some have one at the end as well.
As for OnePiece, any CD from them is a good deal. I love all the tv series Cds and the movie CDs are usually a gamble depending on your tastes. The 'dead-end race' movie (I think movie 3) is hte best of all the music ones to me. Gotta be my fav OnePiece CD entirely. I also like the second tv series cd.
I liked the cds more when I was younger, not that I'm and old man though. :P I had a few CDs but ended up selling most of them, though I riped them before I sold them but I think I lost the data.I still have Slayers TRY Vox CD. I don't really listen to them anymore, well not at all, but I'll keep it just the same.
How ever I love the tenchi movie sound tracks. I have all three, though movie 1 is a burnt CD. :P Tenchi Muyo in love 2 is my fav.