I would have to say Warhawk for obvious reasons.
Ben Daglish was a fave of mine I (and Badtoad
and a couple of others) spent some time on Orange Street at Alligator Software with both Ben and Tony (Rat) Crowther. So, Seeing the system he used to do his music and the nostalgia around that time in my life :- Arc Pandora reigns as one of my FAVE sid tunes (and the couple of mp3 remixes are fantastic also).
Bounces was also a tune that I really liked (the sombre sids were more appealing to me, and harder to achive)
Pachabels Cannon was also a great tune that was on a c64 demo RIGHT in the early days. It was a demo disk with around 6-8 tunes. Fantastic stuff for such an early music demo.