This is basically a list of music I think that would make for some excellent remixes (Besides being good tunes in the first place). Many of them do not have any remixes on this site and for the ones that do, I think more are in order (;^D) . One more thing is that my taste is along the lines of [ techno / industrial / trance / classical ] and I was thinking of something along those lines when making this list. In essence, I'm saying that a jazz remix of most of these tracks wouldn't work very well... 
 
Super Mario RPG
Battle with Culex 
1st Battle with Smithy (where he looks like a diabolical Santa o_0) 
Major Boss Battle (i.e. Axem Rangers, Exor, etc.) 
Mini-Boss battle (i.e. Hammer Bros., Croco, etc.)
 
[*]Chrono Trigger 
 
Battle with Lavos' 2nd form (Inside the shell) 
Final Battle with Lavos
 
[*]Super Mario World 
 
Vanilla Dome Map Screen (Possibly good for a hip-hop type remix) 
Bowser's Valley 
Special Zone 
Star Road 
Ending credits
 
[*]Donkey Kong Country 
 
Gangplank Galleon 
Cranky's Theme 
Funky's Fugue 
Fear Factory 
Forest Frenzy 
Treetop Rock
 
[*]Donkey Kong Country 2 
 
Battle with K.Rool 
Lost World Map Screen 
Ice Cave Level (i.e. Black Ice Battle) 
Jungle Level (i.e. Animal Antics) 
Ship Hold Level
 
[*]Donkey Kong Country 3 
 
Mountain Level (i.e. Kong-Fused Cliffs) 
Pipe Level 
Tree Level (i.e. Ripsaw Rampage) 
Factory Level
 
[*]Plok 
 
Boss battle (i.e. Bobbins Bros., Womack Spider, etc.) 
Beach 
Creepy Crag 
Cavern (The level after Creepy Crag I believe...) 
Fleapit 
Plok's House
 
[*]GoldenEye 007 
 
Antenna Cradle 
Train 
Silo 
Aztec Temple 
Egyptian Temple 
Streets 
Surface 1 
Bunker 2 
Depot 
Nearly all of the "X" versions of the musics are good... 
Pause screen a.k.a "007 Watch Theme"
 
[*]Perfect Dark 
 
Alien Conflict 
Main Menu 
dataDyne Central: Extraction 
Area 51: Escape 
Deep Sea: Nullify Threat (there is an official remix of this I've only heard in USF format which is decent...) 
Nearly all of the "X" versions of the musics are good...
 
[*]Turok 2 : Seeds of Evil 
 
The Death Marshes 
Lair of the Blind Ones 
Hive of the Mantids
 
[*]Star Fox 64 
 
Final Battle with Andross (i.e. The brain, not the face) 
Sector X 
Macbeth / Titania 
Area 6 
Bolse 
Warp Zone 
StarWolf's Theme
 
[*]Legend of Zelda: Ocarina of Time 
 
Forest Temple 
Mid-Boss battle 
Dinosaur Boss Battle (The boss in Dodongo's Cavern has different music than the other bosses) 
Chamber of Sages / Temple of Time / Legend of Hyrule (They're basically the same...) 
Inside Gannon's Castle (This is where Gannon is playing the piano, this is also in Zelda 3 done without piano) 
1st Battle with Gannon 
2nd Battle with Gannon 
Shadow Temple 
Zora's Domain 
Potion Shop
 
[*]Paper Mario 
 
Huffin' And Puffin' (Battle with Huff N Puff) 
King of the Koopas (Final Battle)
 
[*]Doom 
 
E1M8
 
[*]Doom 2 
 
Map 32
 
[*]Doom 64 
 
Into The Void (I think this was used on other maps as well)