Boy, this is difficult.

1. Into the Darkness - Final Fantasy IV Celtic Moon
2. Main Theme - Final Fantasy IV Piano Collection
3. Theme of Love (Arranged Version) - Final Fantasy N Generation
4. My Home, Sweet Home - Final Fantasy V Piano Collection
5. Ahead on Our Way - Final Fantasy V Piano Collection
6. Aria Di Mezzo Carattere (Arranged Version) - Final Fantasy N Generation
7. Opening Theme - Tina - Final Fantasy VI Grand Finale
8. Mystery Train - Final Fantasy VI Grand Finale
9. Main Theme (Orchestrated) - Final Fantasy VII Reunion
10. J-E-N-O-V-A - Final Fantasy VII Piano Collection
11. Ami - Final Fantasy VIII Piano Collection
12. The Man with the Machine Gun - Final Fantasy VIII Orchestra Fithos Lusec Wecos Venosec
13. The Place I'll Return to Someday - Final Fantasy IX Piano Collection
14. A Face Unforgotten - Final Fantasy IX OST
15. Vamo 'Alla Flamenco - Final Fantasy IX Piano Collection
16. To Zanarkand - Final Fantasy X Piano Collection
17. Eternity Memory of Lightwaves - Final Fantasy X-2 Piano Collection
18. Clash on the Big Bridge - Final Fantasy XII OST

Undoubtedly it didn't escape anyone's notice that I prefer piano and arranged versions of the songs. There's so much more I wanted to put on this list, but given the limit...