I rather do not make a ranking. It is very hard for me and basically only the first few have the place I gave them here:

Final Fantasy VII Sepher Sephiroth: One-Winged Angel

Final Fantasy VII - One Winged Angel - YouTube

Final Fantasy XIII Ending: Kimi ga iru kara

FINAL FANTASY XIII Sayuri Sugawara - Kimi ga iru kara - Youtube

Final Fantasy Prelude

Final Fantasy Vocals Collection I: Pray - Prelude - YouTube

Final Fantasy VII Sephiroth's Theme: Those Chosen by the Planet

Final Fantasy VII - Those Chosen by the Planet [HQ] - YouTube

Final Fantasy VII On our Way

Final Fantasy VII - Ahead on Our Way [HQ] - YouTube

Final Fantasy IV Theme of Love

Final Fantasy Pray - 05 - Into the Light (Theme of Love) - YouTube

Final Fantasy VI Terra's Theme/Wanderer of Time

Final Fantasy Pray - 04 - Wanderer of Time (Terra's Theme) - YouTube

Final Fantasy VII Aerith's Theme

Final Fantasy 7 Music - Aerith's Theme - YouTube

Final Fantasy Theme: Final Fantasy/Pray

Final Fantasy Pray - 10 - Pray (Final Fantasy) - YouTube

Final Fantasy VII Main Theme/Cloud's Theme

Final Fantasy VII - Main Theme [HQ] - YouTube

Final Fantasy VI Forever Rachel:

Saddest SNES Music: #1 - Forever Rachel - Final Fantasy 6 - YouTube

The Rest ist without rankings:

Final Fantasy VII Crisis Core Main Theme

Final Fantasy VII Crisis Core - Main Theme - YouTube

Final Fantasy VII Crisis Core The Price of Freedom

Final Fantasy Crisis Core The Price of Freedom (Last Battle Extended) - YouTube

Final Fantasy VIII Eyes on Me

Final Fantasy VIII (eyes on me By faye wong) - YouTube

Final Fantasy X Suteki Da Ne

Suteki Da Ne (Rikki) - YouTube

Final Fantasy IX Over the Hill

https://www.youtube.com/watch?v=EGAWcVKDqxg

Final Fantasy IX Kuja leaves Burmecia

https://www.youtube.com/watch?v=QRSzoseug5g

Final Fantasy VII Interrupted by Fireworks

https://www.youtube.com/watch?v=6Pi9xgOXvTs

Final Fantasy X Yuna's Theme

https://www.youtube.com/watch?v=oIw1sdmRyq8

Final Fantasy VII Dirge of Cerberus Longing

https://www.youtube.com/watch?v=JzG24vGN_H0

Final Fantasy IX Dali Village

https://www.youtube.com/watch?v=elKGnfiwR2E

Final Fantasy VII Those who fight/Fighting

https://www.youtube.com/watch?v=3B_EctHjsR4

Final Fantasy VII Those who fight further/Still more Fighting/Fight on!

Final Fantasy VII - Still More Fighting [HQ] - YouTube

Final Fantasy XIII-2 Last Hunter

Final Fantasy 13-2 OST - Disc Two - 03 - Last Hunter - YouTube

Final Fantasy VI The Decisive Battle

Best VGM 358 - Final Fantasy VI - The Decisive Battle (Boss) - YouTube

Final Fantasy IV Battle with the Four Fiends

FF4, Appearance of Golbez's Four Lords of the Elements - YouTube