I'm trying to make an "essential" list for OSTs, but I'm running into snags. Here's a beta list (title (system) - genre):
1. Tetrisphere (N64) - Puzzle
2. The New Tertis (N64) - Puzzle
3. Touhou 6: Embodiment of Scarlet Devil (Windows) - shmup
4. Touhou 11: Subterrenean Animism (Windows) - shmup
5. Sonic CD Japan (Sega CD) - platform
6. F-Zero X (N64) - racing
7. Pump It Up: Banya discog (Arcade) - music game
8. pop?n music 12 Iroha (Arcade) -music game
9. beatmania IIDX 12th style HAPPY SKY (Arcade) - music game
10. Super Smash Brothers Brawl (Wii) - fighting
11. Super Mario RPG (SNES) - RPG
12. Katamari Damacy (PS2) - Whatever
13. Persona 4 (PS2) - RPG
14. Disgaea (PS2) - RPG
15. Phantom Brave (PS2) - RPG
16. Jet Set Radio (Dreamcast) - platforming and adventure
17. Sonic 3 and Knuckles (Genesis) - platforming
18. Streets of Rage 2 (Arcade) - beat em up
19. Street Fighter 2 (Arcade) - fighting
20. Silent Hill 3 (PS2) - horror
21. Gitaroo Man (PS2) - music game
22. Parappa the Rapper Trilogy (PS1 and PS2) - music game
23. Marvel vs. Capcom 2 (Arcade) - fighting
24. Sonic Adventure (Dreamcast) - platform
25. We Love Katamari (PS2) - whatever
26. Kingdom Hearts (PS2) - RPG
27. Donkey Kong Country 2 (SNES) - platform
28. Doom (PC) - FPS
29. Earthbound (SNES) - RPG
30. Kirby Super Star (SNES) - Adventure
31. Crazy Bus (Trollicom) - Nothing
32. Legend of the Mystical Ninja (N64) - adventure
33. Final Fantasy X (PS2) - RPG
34. Banjo and Kazooie (N64) - Adventure
35. No More Heroes (Wii) - action
36. F-Zero GX (Gamecube) - racing
37. BlazBlue (360) - fighting
38. Tales of Vesperia (360) - RPG
39. Chrono Cross (SNES) - RPG
40. Keyboardmania 3rd mix (Arcade) - Music game
I'm missing a lot of worthwhile titles, and I feel that a good chunk of them can be dropped and replaced. The purpose is to include OSTs of note, whether through the quality of the music, their influential impact, or (in some cases) the infamy behind them, and at the same time, diverse.