I always thought that these Sonic games' music work well with these Kingdom Hearts games:
1-Kingdom Hearts/Sonic Adventure.
2-Chain of Memories/Sonic Heroes.
3-Reverse/Rebirth/Shadow the Hedgehog.
4-Kingdom Hearts II/Sonic Adventure 2.
5-358/2 Days/Sonic Unleashed.
6-Birth by Sleep/Sonic the Hedgehog 2006.
8-Dream Drop Distance/Sonic Generations.
9-A Fragmentary Passage/Sonic Lost World.
and then hopefully lastly
10-Kingdom Hearts III/Sonic Forces.
what does everyone think?