Go to the Videogame Music Archive at http://www.vgmusic.com if you're looking for a web site that contains a lot of videogame music; this page only has videogame midis that I've sequenced.
 

SNES (Super Nintendo):
   Prince of Persia - Intro, Level 1
   Star Fox - Corneria
   ActRaiser - Fillmore 1, Bloodpool 1, Birth of a People
   Mega Man X - Fortress 1
NES (Nintendo):
   Gradius - Level 4
   Marble Madness - Races: Practice, Beginner, Intermediate, Aerial, Silly, Ultimate
   Solstice - Title Screen
   Ultima: Exodus - Ambrosia, Battle, Castle, Cave/Title Screen, King, Overworld, Sail, Town
   Gauntlet - A, B, C, D, Secret Room, Treasure Room
   Zelda - Title Screen, Level 9, Secret Discovery
   Tetris - 1, 2, 3
   Faxanadu - Title Screen
   Solomon's Key - Main
   Ghosts 'n Goblins - Level 1
   Super Mario Brothers - Main, Underwater
ARCADE:
   Galaga - Game Start
   Mrs. Pac-Man - Game Start, Act I, Act II
PSX (Sony Playstation):
   Final Fantasy 7 - Battle, Boss Battle (NOTE: I didn't make these two)