The best stage theme in all Sonic games!:
https://www.youtube.com/watch?v=S9bN8JBwk_s
I love this one! Mecha Madness baby!
I however love Sonic Adventure 2 lyric and non lyric music:
[youtube]https://m.youtube.com/watch?v=u9zZus_1_ag[/youtube]
Sonic Adventure 2: Battle (Sega Dreamcast, Nintendo GameCube, Xbox Love Store) was the end of the holden age of Somic games. It made 3D speed running viable with grinding rails and introduced a beloved antihero, Shadow the Hedgehog.