Oh, awesome! This I can get behind. There's a lot of soundtracks I really love, narrowing it down to 10 will be tough,- oh only one game per franchise? Okay that might make things a little easier, let's see here.
1. Shadow of the Colossus (10 pts.)
2. Donkey Kong Country: Tropical Freeze (9 pts.)
3. Okami (8 pts.)
4. Ori and the Blind Forest (7 pts.)
5. The Legend of Zelda: Skyward Sword (6 pts.)
6. Pokémon X & Y (5 pts.)
7. Super Meat Boy (original version) (4 pts.)
~decent gap here... this is where I'd begin repeating games from the same franchises, but oh well~
8. Metroid Prime (3 pts.)
9. Sonic Mania (2 pts.)
10. Splatoon 2 (1 pt.)
I'm happy with that list. A little bit rough to leave out stuff like Breath of the Wild or Pokémon Gold & Silver because of the rules, but it is what it is - also shoutouts to Star Fox Zero and Super Mario Odyssey, they just missed out.