Here are a few I've long wanted to hear remixed - some are a bit slow and haunting, but from what I've heard from remixers like Chronberg, that doesn't always need to be an obstacle!
Martin Walker's Citadel, Track 1 (sooo awesome, love this SID - would be a real challenge I'd guess) -- I don't think it would take much updating, and would like to hear a lot of the original SID sounds mixed with some atmospheric echo noise:
http://www.slayradio.org/sid_info.php?s ... itadel.sid
Below the Root, Track 1 (no existing remixes - a simple but enduring tune that stuck with me over the years) - Something along the lines of Chronberg's "Heartland" (http://remix.kwed.org/files/RKOfiles/Ch ... remix).mp3) - but with this tune would be mind-blowin' methinks:
http://www.slayradio.org/sid_info.php?s ... e_Root.sid
Necromancer, Track 1 (there is one existing remix but I was hoping for something more upbeat in nature - like Yoko's Target Renegade (http://remix.kwed.org/files/RKOfiles/Yo ... ix)%20.mp3)

http://www.slayradio.org/sid_info.php?s ... mancer.sid
Realm of Impossibility, Tracks 1, 2) - I can see some possibilities with this one, probably should be slowed down by about half with a loud Dance/Club sound with a thumping beat would be sweet - ( something like Chronberg's Gyroscope http://remix.kwed.org/?search_id=3151 ):
http://www.slayradio.org/sid_info.php?s ... bility.sid
Cheers!

-RMason C64Walkabout.com
PS - I'd love to do an interview with said remixer like the one I did here with Chronberg: http://c64walkabout.com/2008/10/02/excl ... nberg.aspx