Puggo - Jar Jar's Yoda said:
One of the great versions of "Imperial March" is on the Telarc demonstration disc called "Star Tracks". It has the Cincinnati orchestra directed by Erich Kunzel. There are some other SW, ST, and Raiders pieces also (including "Luke and Leia"). The sound quality is awesome and the performances true to the originals. It's probably out of print but easy to find on eBay.
Shame John Williams wouldn't conduct a new set for Telarc. That would be amazing.