While the game quality of 06, Unleashed, and Colors varies from terrible to fun, all three games from that era had some really fun/memorable tracks.

06: https://www.youtube.com/watch?v=qAx3hTZeyBw

Unleashed: https://www.youtube.com/watch?v=SWMcIB7XIi0

Colors main theme: https://www.youtube.com/watch?v=5eUswq5owJk

Color's stage music: https://www.youtube.com/watch?v=IjtE4nPMN5g

I have no music background and the colors theme chorus is absolutely an earworm, but sonic music is just fun.