you can find a wonderful source for all the great LucasArts soundtracks! I'm not quite sure how legal that site is. But it has been there for many, many years now and it seems that nobody attempted to take them down. I strongly hope Disney won't start a campaign against it anytime soon...
That's my website, by the way.
And regarding legality: A couple of years ago (at the end of 2004) I got contacted by LucasArts PR department. First of all, it was cool of them that it wasn't their legal department, but a very nice PR lady, Ronda Scott. Back then I still had a lot of Star Wars and Indiana Jones game soundtrack on my site as well. Anyway, she told me that the rights holder of those IPs (she couldn't exactly tell me who, but I assume RCA, Paramount or Sony... whoever possesses the rights to those franchises' soundtracks) contacted Lucasfilm's legal department to have them make me take down those soundtracks. Furthermore Ronda told me that they had no problem with me hosting all those other soundtracks, since those weren't external IPs, but LucasArts' own stuff and they were okay with it. So, that's that.
Oh, my! A legend replying to my post! :D
Thank you for sharing that piece of information! It's very interesting to know that LucasArts handled this case in such a friendly manner. I'm sure there're companies out there, who'd immediately send out their legion of lawers to protect their copyrighted material.
And of course thank you very much for hosting the music and keeping the site alive for such a long time!