One CD I like a lot is [url]http://www.amazon.com/exec/obidos/ASIN/B000006OGX/qid=1025391314/sr=2-1/ref=sr_2_1/002-5459054-2609602[/url].
Also, Emerson, Lake, & Palmer do some pretty interesting adaptations of classical music (Copland's "Hoedown" and "Fanfare for the Common Man", Blake's "Jerusalem", and lots of stuff by Mussorgsky, Prokofiev, among others.)
Styx did some as well - a rendition of Handel's "Messiah Chorus" with the 5 band members on vocals and Dennis DeYoung on St James' Cathedral's pipe organ, and Bach's "Little Fugue in G," again with DeYoung on the pipe organ. (He also plays the Cathedral's organ in "I'm OK" on the Pieces of Eight album.)
I like John Williams' music a lot, too (Star Wars did it to me!) and I desperately hope that I can pick up "Pops Goes the Fourth" on my TV this coming Thursday!