How about "favorite GHZ themes"?
- Sonic 1's*
- Sonic 2 (8-bit)
- Sonic Chaos/Sonic & Tails**
- Sonic Drift
- Sonic Blast/G Sonic
- Sonic Advance**
*I dunno if reused compositions like those appearing in 8-bit, Adventure 2, and Generations count (to say nothing of the surprising reuse of
Neo Green Hill Zone) but discussion about the merits between multiple versions is both likely and welcome.
**Are "Mecha" and "Neo" pushing the definition? Even if Mecha reuses Green Hills Zones music, which itself is just YCDA, I think its different enough. (And, no, I don't think 2 8-bit's pluralizing "hills" is significant to even factor.)