Basically the same as
SuperCraig64's topic, except organized differently and more up-to-date.
MM1SEL ~ Game Start
CUTMUS ~ Cut Man Stage
GUTMUS ~ Guts Man Stage
ICEMUS ~ Ice Man Stage
BOMMUS ~ Bomb Man Stage
FIRMUS ~ Fire Man Stage
ELEMUS ~ Elec Man Stage
MM1BOSS ~ Boss
MM1VIC ~ Stage Clear
1DW1MUS ~ Dr. Wily Stage 1
1DW2MUS ~ Dr. Wily Stage 2
MM1WBOSS ~ Dr. Wily Stage Boss
D_DM2TTL ~ Opening
MM2TITL ~ Title
D_DM2INT ~ Password
MM2SEL ~ Game Start
METMUS ~ Metal Man Stage
AIRMUS ~ Air Man Stage
BUBMUS ~ Bubble Man Stage
QUIMUS ~ Quick Man Stage
CRAMUS ~ Crash Man Stage
FLAMUS ~ Flash Man Stage
HEAMUS ~ Heat Man Stage
WOOMUS ~ Wood Man Stage
MM2VIC ~ Stage Clear
2DW1MUS ~ Dr. Wily Stage 1
2DW3MUS ~ Dr. Wily Stage 2
2DW4MUS ~ Last Stage
MM2BOSS ~ Boss
MM3GO ~ Password
MM3SEL ~ Game Start
NEEMUS ~ Needle Man Stage
MAGMUS ~ Magnet Man Stage
GEMMUS ~ Gemini Man Stage
HARMUS ~ Hard Man Stage
TOPMUS ~ Top Man Stage
SNAMUS ~ Snake Man Stage
SPAMUS ~ Spark Man Stage
SHAMUS ~ Shadow Man Stage
MM3BOSS ~ Boss
MM3VIC ~ Stage Clear
3DW1MUS ~ Dr. Wily Stage 1
3DW2MUS ~ Dr. Wily Stage 2
3DW3MUS ~ Dr. Wily Stage 3
MM3BOSS2 ~ Dr. Wily Stage Boss
MM3CRE ~ Staff Roll
MM4INT ~ Opening
MM4SEL ~ Game Start
BRIMUS ~ Bright Man Stage
TOAMUS ~ Toad Man Stage
DRIMUS ~ Drill Man Stage
PHAMUS ~ Pharaoh Man Stage
RINMUS ~ Ring Man Stage
DUSMUS ~ Dust Man Stage
DIVMUS ~ Dive Man Stage
SKUMUS ~ Skull Man Stage
MM4ITEM ~ Get Items
MM4BOSS ~ Boss
MM4VIC ~ Stage Clear
4DC1MUS ~ Dr. Cossack Stage 1
4DC2MUS ~ Dr. Cossack Stage 2
4DW1MUS ~ Dr. Wily Stage 1
MM4BOSS2 ~ Last Boss
GAMEWIN ~ All Stage Clear
COSSVIC ~ Ending
MM4GO ~ Game Over + Password (rather awkwardly edited together, I may add)
MM5SEL ~ Game Start
GRAMUS ~ Gravity Man Stage
WAVMUS ~ Wave Man Stage
STOMUS ~ Stone Man Stage
GYRMUS ~ Gyro Man Stage
STAMUS ~ Star Man Stage
CHAMUS ~ Charge Man Stage
NAPMUS ~ Napalm Man Stage
CRYMUS ~ Crystal Man Stage
MM5BOSS ~ Boss
5CASTLE ~ Dark Man Stage Map
DARMUS ~ Dark Man Stage
5DW1MUS ~ Dr. Wily Stage
MM5BOSS2 ~ Final Boss
MM5CLEAR ~ All Stage Clear
MM6SEL ~ Game Start
BLIMUS ~ Blizzard Man Stage
CENMUS ~ Centuar Man Stage
FLMMUS ~ Flame Man Stage
KNIMUS ~ Knight Man Stage
PLAMUS ~ Plant Man Stage
TOMMUS ~ Tomohawk Man Stage
WNDMUS ~ Wind Man Stage
YAMMUS ~ Yamato Man Stage
MM6BOSS ~ Boss
MRXMUS ~ Mr. X Stage
6DW1MUS ~ Dr. Wily Stage
MM6BOSS2 ~ Final Boss
TORNWIN ~ All Stage Clear
NEWINT ~ Ending (Staff Roll portion)
7INTMUS ~ Opening Stage -- Cover by Dr. Freeman
MM7BASS ~ Theme of Bass -- Cover by Dr. Freeman
MM7SEL ~ Game Start -- Cover by ???
FREMUS ~ Freeze Man's Stage -- Cover by OrangeMario
JUNMUS ~ Junk Man's Stage -- Cover by Famitard
BURMUS ~ Burst Man's Stage -- Cover by Famitard
CLOMUS ~ Cloud Man's Stage -- Cover by Famitard
SPRMUS ~ Spring Man's Stage -- Cover by Famitard
SLAMUS ~ Slash Man's Stage -- Cover by Famitard
SDEMUS ~ Shade Man's Stage -- Cover by Famitard
TURMUS ~ Turbo Man's Stage -- Cover by Famitard
MM7BOSS ~ Boss -- Cover by ???
7DW1MUS ~ Dr. Wily Stage 1 -- Cover by Dr. Freeman
7DW2MUS ~ Dr. Wily Stage 2 -- Cover by Dr. Freeman
7DW3MUS ~ Dr. Wily Stage 3 -- Cover by Famitard
7DW4MUS ~ Dr. Wily Stage 4 -- Cover by Famitard
MM7OBOS ~ Dr. Wily Stage Boss -- Cover by ???
MM7FBOS ~ Final Boss -- Cover by Dr. Freeman
MM7VIC ~ All Stage Clear -- Cover by ???
MM7END ~ Staff Roll -- Cover by ???
MM7BASS2 ~ Unused Track -- Cover by LlamaHombre
MM8INT ~ Opening Stage Part 1 -- Cover by OrangeMario
CTFBOSS3 ~ Mid Boss -- Cover by ???
MM8SEL ~ Stage Selected -- Cover by ???
FROMUS ~ Frost Man Stage -- Cover by Famitard
CLNMUS ~ Clown Man Stage -- Cover by Famitard
TENMUS ~ Tengu Man Stage (PS1) -- Cover by Famitard
GREMUS ~ Grenade Man Stage -- Cover by Famitard
DUOMUS ~ Theme of Duo (U-GEN Remix) -- Cover by OrangeMario
SWOMUS ~ Sword Man Stage -- Cover by Famitard
AQUMUS ~ Aqua Man Stage -- Cover by Famitard
ASTMUS ~ Astro Man Stage -- Cover by Famitard
SEAMUS ~ Search Man Stage -- Cover by Famitard
MM8BOSS ~ Boss -- Cover by ???
8DW1MUS ~ Dr. Wily Stage 1 -- Cover by ???
8DW2MUS ~ Dr. Wily Stage 2 -- Cover by OrangeMario
8DW3MUS ~ Dr. Wily Stage 3 -- Cover by OrangeMario
8DW4MUS ~ Dr. Wily Stage 4 -- Cover by ???
CREDMUS2 ~ Staff Roll -- Cover by ???
TENMUS2 ~ Tengu Man Stage (SS) -- Cover by OrangeMario
ENDMUS ~ Opening 1
ARREST ~ Opening 2
CONMUS ~ Concrete Jungle (Concrete Man Stage)
TORMUS ~ Thunder Tornado (Tornado Man Stage)
SPLMUS ~ Splash Blue (Splash Woman Stage)
PLUMUS ~ Plug Electric (Plug Man Stage)
JEWMUS ~ Jewel Temptation (Jewel Man Stage)
HORMUS ~ Hornet Dance (Hornet Man Stage)
MGMMUS ~ Magma Burning (Magma Man Stage)
GALMUS ~ Galaxy Fantasy (Galaxy Man Stage)
MM9BOSS ~ Boss
D_STWIN ~ Shop
D_STLOSE ~ Suspense (sounds really off here, for some reason)
9DW1MUS ~ Flash in the Dark (Dr. Wily Stage 1)
9DW2MUS ~ We're the Robots (Dr. Wily Stage 2)
9DW3MUS ~ Strange World (Dr. Wily Stage 3)
9DW4MUS ~ Castle of Evil (Dr. Wily Stage 4)
MM9FBOS ~ Wily Machine
CREDMUS ~ Staff Roll
FAKMUS ~ Overdrive Scramble (Special Stage)
9ENDLESS ~ Maze of Death (Endless Stage)
MM10INT ~ Future World
MM10SUSP ~ Suspicion
TOGETH ~ Go Together
MM10TITL ~ Title
MM10SSEL ~ Stage Select
MM10SEL ~ Game Start
BLAMUS ~ King of Blades (Blade Man Stage)
PUMMUS ~ Polluted Pump (Pump Man Stage)
COMMUS ~ Desert Commando (Commando Man Stage)
CHIMUS ~ Absolute Chill (Chill Man Stage)
SHEMUS ~ Cybersheep's Dream (Sheep Man Stage)
STRMUS ~ Fireball Strike (Strike Man Stage)
NITMUS ~ Nitro Rider (Nitro Man Stage)
SOLMUS ~ Solar Inferno (Solar Man Stage)
MM10BOSS ~ Boss
MM10VIC ~ Stage Clear
WILYVIC ~ Shop -Bass-
MM10CRI ~ Crisis
WILYCRI ~ Evil Wily
10ROLL ~ For You -Roll's Theme-
10CASTLE ~ Dr. Wily Castle
MM10RAIN ~ Silent Rain (Dr. Wily Stage 1)
MM10OBOS ~ Dr. Wily Stage Boss
10DW1MUS ~ Abandoned Memory (Dr. Wily Stage 1)
10DW2MUS ~ Against the Pressure (Dr. Wily Stage 2)
10DW3MUS ~ No Turning Back (Dr. Wily Stage 3)
10DW4MUS ~ Stairway to Darkness (Dr. Wily Stage 4)
MM10FB ~ Dr. Wily Machine
10DW5MUS ~ Deep in Space (Dr. Wily Stage 5)
MM10FBOS ~ Dr. Wily Capsule
MM10WIN ~ All Stage Clear
MM10CRE ~ Staff Roll
ENKMUS ~ Heart of Enker (Special Stage 1)
PUNMUS ~ Get the Punk Out (Special Stage 2)
BALMUS ~ Farewell to Ballade (Special Stage 3)
ENKMUS2 ~ Wily Station Stage -- Cover by OrangeMario
PUNMUS2 ~ Wily Station Stage -- Cover by LlamaHombre
MMIVTITL ~ Title / Opening (the only Game Boy song left in its original LR35902 form instead of getting a 2A03 cover)
BALMUS2 ~ Wily Battleship Stage -- Cover by Dr. Freeman
MMIVFBOS ~ Final Battle -- Cover by DynamiteMan.exe
SADCRED ~ Ending 2 -- Cover by ???
MMVTITL ~ Title
MMVSEL ~ Stage Start
MERMUS ~ Mercury Stage
VENMUS ~ Venus Stage
MARMUS ~ Mars Stage
RUSHSPA ~ Rush Space
JUPMUS ~ Jupiter Stage
SATMUS ~ Saturn Stage
PLTMUS ~ Pluto Stage
URAMUS ~ Uranus Stage
TERRAI ~ Terra
MMVBOSS ~ Boss Battle
MMVVIC ~ Stage Clear
MMVWST ~ Stardroids / Wily Star
MMVSSH ~ Space Shooting Stage
VDW1MUS ~ Dark Moon Stage / Wily Star Stage
MMVFBOS ~ Sunstar
MMVWIN ~ All Clear
WTSELECT ~ Game Select / Dr. Light Lab -- Cover by ???
MMWTSEL ~ Wily Tower: Game Start -- Cover by ???
BRGMUS ~ Wily Tower: Buster Rod G Stage -- Cover by OrangeMario
MWSMUS ~ Wily Tower: Mega Water S Stage -- Cover by OrangeMario
HSHMUS ~ Wily Tower: Hyper Storm H Stage -- Cover by OrangeMario
MMWTBOSS ~ Wily Tower: Boss Battle -- Cover by OrangeMario
MMWTVIC ~ Wily Tower: Stage Clear -- Cover by ???
WTDW1MUS ~ Wily Tower: Wily Tower Stage 1 -- Cover by LlamaHombre
WTDW4MUS ~ Wily Tower: Wily Tower Stage 4 -- Cover by Hertzdevil
WTWIN ~ Wily Tower: All Stages Clear -- Cover by ???
MMWCRE ~ Wily Tower: Ending -- Cover by ???
MMBTITLE ~ Title -- Cover by ???
MMBSAVE ~ Data Select -- Cover by ???
MUSMUS ~ Opening Stage -- Cover by OrangeMario
MMBSEL ~ Stage Start -- Cover by ???
DYNMUS ~ Dynamo Man Stage -- Cover by OrangeMario
COLMUS ~ Cold Man Stage -- Cover by OrangeMario
GROMUS ~ Ground Man Stage -- Cover by Musashiaa
PIRMUS ~ Pirate Man Stage -- Cover by Famitard
BRNMUS ~ Burner Man Stage -- Cover by OrangeMario
MGCMUS ~ Magic Man Stage -- Cover by OrangeMario
TENMUS3 ~ Tengu Man Stage -- Cover by Famitard
ASTMUS2 ~ Astro Man Stage -- Cover by OrangeMario
MMBBOSS ~ Boss -- Cover by Famitard
MMBKING ~ King Stage -- Cover by OrangeMario
MMBDW ~ Wily Stage -- Cover by OrangeMario
MMBOBOS ~ King / Wily Battle -- Cover by OrangeMario
MMBGO ~ Game Over -- Cover by ???
GUTSBOSS ~ Stage 3 (from Guts Man's Theme) -- Cover by Dr. Freeman
CTFMUS9 ~ Wood Field -- Cover by Musashiaa
CTFMUS8 ~ Wily Field -- Cover by MegaCocoRock
DRLIGHT ~ Opening Stage -Theme of Mega Man- -- Cover by ???
MM1PWILY ~ Wily Event -- Cover by Dr. Freeman
TIMMUS ~ Time Man Stage -- Cover by OrangeMario
OILMUS ~ Oil Man Stage -- Cover by OrangeMario
MM1PINT ~ Boss Battle (Dialogue) -- Cover by ???
MM1PBOSS ~ Boss Battle -- Unused cover from Rockman 8 FC
MM1PWINT ~ Wily Castle Boss Battle (Dialogue) -- Cover by Dr. Freeman
MM1PWBOS ~ Wily Castle Boss Battle -- Cover by Dr. Freeman
SAROUTS -- Cover by ???
SARRUIN ~ Discovering Purpose -- Cover by OrangeMario
SARFBOS ~ Battle Theme -- Cover by OrangeMario
CTFMUS6 ~ Bubble Crab (from Mega Man X2) -- Cover by Baiilsilisk
CTFMUS4 ~ Trash Man (from Mega Man Super Fighting Robot)
CTFMUS7 ~ Yoyo Man's Stage (from Mega Man Unlimited)
CTFMUS10 ~ Circuit Man (from Mega Man Rock Force)
CTFMUS15 ~ Photon Man (from Mega Man Rock Force)
GHOULS ~ Stage Theme 01 (from Ghost N' Goblins)
D_TTFTW ~ The Moon (from Ducktales)
D_E1M4 ~ Kitchen Ace (and Taking Names) (from Doom) -- Cover by ???
CTFMUS18 ~ Slow Moon (from Streets of Rage 2) -- Cover by icesoldier
CTFMUS19 ~ Area B (from Shatterhand)
CTFMUS20 ~ Fortress (from Ganbare Goemon 2: Kiteretsu Shougun Magginesu) -- Cover by IKA
CTFMUS21 ~ Stage 2-1 (from Ninja Gaiden 3)
CTFMUS24 ~ Stardust Speedway Past (from Sonic CD) -- Cover by Postapocolyptia
CTFMUS25 ~ Streets of Desolation (from Batman)
CTFBOSS1 ~ Boss Battle (from Disney's TaleSpin)
CTFBOSS2 ~ Boss Battle (from Ufouria)
CTFBOSS4 ~ Nightmare (from Kirby's Adventure)
CTFBOSS5 ~ Super Shredder Battle (from Teenage Mutant Ninja Turtles III: The Manhattan Project)
COSSBOSS ~ Cossack Stage Boss (by RushJet1) -- 2a03 conversion by Dr. Freeman
CTFMUS1 ~ Original Track 07 (by Baiilsilisk)
CTFMUS2 ~ Stage 42 (by kevvviiinnn)
CTFMUS3 ~ Stage 20 (by kevvviiinnn)
CTFMUS5 ~ Clockwork Factory (by Mr.X)
CTFMUS11 ~ Frigid Ocean (by Mr.X)
CTFMUS12 ~ Molten Mountain (by Mr.X)
CTFMUS13 ~ Penguins of the Apocolypse (by FearTheDark)
CTFMUS14 ~ Rope (by Javel)
CTFMUS16 ~ Power Shot! (by Wally Chantek)
CTFMUS17 ~ MetalMouth Vulture (by Baiiis8Bit)
CTFMUS22 ~ Highway Lottery (by Donutshoes)
CTFMUS23 ~ Bullet Bounce (by RushJet1)
GUTSBUTT ~ Untitled sting (apparently not from DiC's Mega Man cartoon) -- Cover by ???
MM8BDM ~ Theme of Mega Man 8-Bit Deathmatch -- By OrangeMario and Dr. Freeman
MM8BDMIN ~ Theme of Mega Man 8-Bit Deathmatch (Intro ver.) -- By OrangeMario and Dr. Freeman
PROMTEAM ~ Against the Odds -- By OrangeMario
MM1PWIL6 ~ The Great Genius Dr. Wily -- By Dr. Freeman
GTENSION ~ Gamma Cometh -- By Dr. Freeman
ERBATTLE ~ Evil Robot Battle -- By RushJet1
ERBESERK ~ Evil Robot Battle (Beserk ver.) -- By RushJet1
MMWTFBOS ~ Journey to Genesis -- By OrangeMario and RushJet1
PROMBOSS ~ A Case of the Blues -- By OrangeMario
FAKEBOSS ~ Untrustworthy Cops -- By OrangeMario
QUINTRO ~ Temporanomaly (intro) -- By Dr. Freeman
QUIBOSS1 ~ Temporanomaly (Phase 1) -- By Dr. Freeman
QUIBOSS2 ~ Temporanomaly (Phase 2) -- By Dr. Freeman
QUIBOSS3 ~ Temporanomaly (Phase 3) -- By Dr. Freeman
QUIBOSS4 ~ Temporanomaly (Phase 4) -- By Dr. Freeman
QUIBOSS5 ~ Temporanomaly (Phase 5) -- By Dr. Freeman
QUIINT ~ Temporanomaly (Phase 5 end) -- By Dr. Freeman
RBNZAINT ~ Your World, Our World -- By Dr. Freeman
MMIVFBOL ~ MMIV Final Battle (with sample from Unused Theme) -- By DynamiteMan.exe
MMIVDKIN ~ Duo of Kings (intro) -- By OrangeMario and Dr. Freeman
MMIVDUOK ~ Duo of Kings -- By OrangeMario and Dr. Freeman
TERRTALK -- By ???
COSSPACE -- By ???
NEPMUS (This the 2A03 Remake version of MMV's Neptune Stage theme, edited by ??? to give the tempo of the original LR35902 version)
TERRAATK -- By ???
TERRABOS ~ The Galactic Conqueror -- By OrangeMario and Dr. Freeman
MMKFBOS -- By ???
SUNTENSE -- By ???
SUNBOSS1 ~ The Doomsday Weapon -- By Dr. Freeman
ECLIPINT ~ Thy World Consumed (Intro only) -- By Dr. Freeman
SUNBOSS2 ~ Supernova -- By Dr. Freeman
SUNBOSST ~ Supernova (Terra's appearance) -- By Dr. Freeman
ECLIFBOL ~ Thy World Consumed (Full track) -- By Dr. Freeman
ECLIFBOS ~ Thy World Consumed (Main track only) -- By Dr. Freeman
8BDMFDUO ~ For Everlasting Peace (Duo speaks) -- By Dr. Freeman and OrangeMario
8BDMFINT ~ For Everlasting Peace (Intro) -- By Dr. Freeman and OrangeMario
8BDMFBOS ~ For Everlasting Peace -- By Dr. Freeman and OrangeMario
8BDMFIN ~ For Everlasting Peace (Finale) -- By Dr. Freeman and OrangeMario
MMVEND (This the 2A03 Remake version of MMV's ending theme, edited by ??? to end properly instead of looping)
MGICPAST -- By ???
MGICPRES -- By ???
STATIK ~ Static
AMBFIRE ~ Fire
RBNZASTA ~ Roboenza infection
AMBSTARS ~ Stardroids in space