Yeah, like Drake I too know some cracktros which feature C64 chip-tunes. My favourite is a tune of Commando (courtesy Rob Hubbard) which is used in a cracktro of Global Gladiators.
Another one is The Last V8 (also courtesy Rob Hubbard) which is featured in a cracktro of Cannon Fodder.
What makes this thread interesting is the quality of a gametune on C64 and Amiga. Sure, the Amiga has better sound capabilities but some songs just sound better on C64.
Listen for example to Mr Heli on Amiga and compare it to its C64 counterpart. The C64 version by Maniacs of Noise rocks with its fast toe-tapping tunes. The Amiga tune is a let down and sounds more like an Argentinian Tango than a fast and exciting tune for a game.
This is also true for Switchblade 1: The ingame music sounds okay on Amiga but play the song on C64 Switchblade 1 and it sounds like it was written with a C64 in mind.