The Castlevania Series:
Whatever MIDI's I don't have.
Final Fantasy VII:
Any MIDI's other than the battle and boss themes from the Playstation Demo
Super Street Fighter II: The New Challengers:
Dee Jay's Stage, Fei Long's Stage, T. Hawk's Stage & Sagat's Ending.
Double Dragon II
All the stages other than stage 1.
The Legend of Zelda: Link's Awakening
The Ending Ballad of the Windfish (when you have all the instruments).
The Legend of Zelda: A Link to the Past
The music from the forest, when in the darkworld.
Megaman (Nintendo Series)
Anything you have that I don't.
Wizards and Warriors
The main theme.
Shadowgate (NES)
Any MIDIs.