I got my hands on 5 different Commodore 64 SID revisions (6581 R2 R3 R4 R4AR and 8580 R5) so it seemed obvious that a comparison would be a good idea. So I did it.
Started with a track that has been composed on a 6581 SID, recorded it with all the 5 different chips and wrote a post about the procedure. Then I thought it would be fair to do the same thing with a 8580 track and record it through all 6581's as well.
The result is a 3 part article with audio examples, waveform screenshots, some additional information and conclusion. Bring some cold beer, chips, etc. and follow these links:
SID shootout Part 1.
SID shootout Part 2.
SID shootout Part 3.
I've chose nice demoscene music instead of well-known game soundtrack because these ones are great to listen to and also show serious sound design skills, sometimes I felt the SID was crying while producing the audio.
Enjoy.