Name says it all. What soundtracks from the Sega Genesis do I and everyone else currently need to make our lives complete? What tracks from each soundtrack come most recommended? Feel free to put down duplicates on other systems (ex: Ys III, Cool Spot).

Seeing as how I hope people recommend obscure stuff I've never heard of, I'll state the obvious:

Sonic 1-3 - Yadda, yadda, yadda...Need I say more? Other than Sonic 2's music is probably one of my favorite soundtracks of all-time (Special Stage, Metropolis Stage and Chemical Plant stand out the most, but it's all good) and those Sonic 3 boss themes just plain rock.

Phantasy Star 2-4 - Hard to believe by the first dungeon, you've heard roughly half the music from PSII. I can live off the main overworld and battle theme from II and Behind the Circuit/Cybernetic Carnival from IV. Love both of those scores, while 3 isn't bad in its' own right.

Thunder Force II-IV - Had an idea of how good some of the originals were from the "Broken Thunder" album. Back to the Fire from III got about an hour worth of playtime today, between work, the ride to work and sitting at the computer. Could've gone more, but I had to give the other stuff I had with me a chance. The bassline in Death's Face (II) is also permanently stuck in my head and the original "Knights of Legend" (II also) and "Stand Up Against Myself" (IV) were both incredible.

Gleylancer - Hey, Iwadare can write great shmup music! Not as intense as the Thunder Force soundtracks, but rocks nonetheless.

The entirety of Thunderforce III is brilliant. More Technosoft goodness comes from Elemental Master (Stages 1 and 2).

I've always been very fond of the first two stage tunes from Hellfire.

From Granada X I'd pick Heavy Line, Windy Avenue, and Nature Trail (Sakuraba!).

Sakuraba: Arcus Odyssey, Earnest Evans, El Viento, Final Zone, Granada, Sol-Deace, Zan

Koshiro: Streets of Rage 1-3, particularly 2

Jesper Kyd: Adventures of Batman and Robin

Michiru Yamane: Castlevania Bloodlines

Sakimoto/Iwata: Gauntlet IV

Shining Force II: "To Arms" and "Water Goddess Mitula"

Toejam and Earl 2

Skitchin'

Rocket Knight Adventures - stages 5-7

Gaiares

some of the Ecco stuff (yay melodic percussion)

<3 FM synth

You gotta love the 16-bit era.  And I agree that Sonic 2 has the best soundtrack of the Sonic games.  One of the best in all of gaming, really.

Streets of Rage 2: Virtually everything is GREAT. There's a reason that this soundtrack is in my top five of all time.  It's the perfect beat 'em up soundtrack.  None are better.

Sagaia/Darius 2: It's all about Olga Breeze (Sun stage in the game) and Planet Blue (Earth stage in the game).   The two boss themes are great too. (one is mysterious and the other makes you feeling like dancing) This soundtrack does well at capturing the mystique of outer space.

Valis III: Came out first for the TG-16 (CD) but I was introduced through the Genesis game.  Forest & Lake (Valis Sword!), Ice World (The Battle of Valis Part 4), and Factory (The Battle of Valis Part 3) are all great.  Btw, the names in parantheses are from the soundtrack release.

Toejam & Earl series:  The first game is chock full of classic tunes and the second has some good ones as well.  Alien Break Down from the first game Lewanda's Love from the second are probably my faves from each game.

Revenge of Shinobi: Yuzo Koshiro + Over the Bay... (trying to make THAT jump made this song forever memorable)  Nuff said.

Ecco 1 & 2: From the first game, Jurassic Beach + The Vents + Island Zone.  From the second game, Crystal Springs + Skyway + Tube of Medusa.  Who needs Spencer Nilsen's Sega CD stuff?

Shining Force: All the battle themes are good and I've always liked the Castle theme as well.  Epic and to the point is what the music in this game is about.

Oh, and "Sinking Old Sanctuary" from Bloodlines is still my favorite track of anything that Yamane has done in Castlevania.  Both the original and Circle of the Moon versions are great.

Streets of Rage series: Yuzo at his finest, still to this day.  2 > 1 > 3.

Light Crusader: Highly underrated game by Treasure, music by Aki Hata.  Whole soundtrack owns, some super catchy tunes here.

Verytex: Pretty fun shooter with some killer music by Sakimoto and Iwata.

Castlevania Bloodlines: Some of Yamane's best stuff here.  I gotta agree with Megavolt on this one too, The Sinking Old Sanctuary is spectacular and really stands out.

Sonic 1-3, & Knuckles, 3D Blast: Sonic 2 being the big winner here, with extra nostalgia points going to Sonic 1.  3D Blast's soundtrack is pretty underrated and blows the Saturn version away if you ask me.

Golden Axe series: Surprised no one mentioned these yet.  First one takes the cake but II and III had some nice stuff too.  Sutakora, Sassa!

Toejam & Earl: Classic music to one of the weirdest games from my childhood.

I could keep going but I'll stop for now cause I'm tired.  Good thread GoldfishX, glad to see the Genesis getting some love.

-Mike

Castle of Illusion Starring Mickey Mouse will always remain my Genny score fave.  That happy-go-lucky forest theme...... the proud Toyland anthem march.... the adventurous romp through Milk 'n Candyland.  Most of the stages were stylistically crafted around that one catchy melody, and I thought it was a great musical approach back in the day.  And nothing can beat that adrenaline-pumping boss battle theme.   

Cool Spot is a given.  One of the Tallarico greats; Western Tune, Rave Dance Tune, and Wall Tune are my favorites.  The FM synth quality does come off sounding better than its SNES counterpart, too.

Where on earth is the Herzog Zwei love?  Sniper, Sleight of Hand, Dawn of A New Age.... this soundtrack screamed for an arrangement treatment.

I almost forgot about Ristar.  The "Intrusion/Du-Di-Da!!" music stands out most to me but the whole soundtrack is good.

I've also always been very fond of the Stage 1 music from McDonald's Treasureland Adventure (which coincidentally is a Treasure game).

Sword of Vermilion (catchy stuff) and Insector X (which was fortunate enough to get arrangement treatment) also had good soundtracks.

Phantasy Star 2,3, and 4 are my holy grails.

But then, you have Shining Force 1 and 2.

Landstalker.

Light Crusader.

Sonic 2 and 3/Knuckles.

Streets of Rage II.

Sword of Vermillion.

Castlevania Bloodlines.

Exile.

Shinobi 3.

Gunstar Heroes.

El Viento.

Columns.

Ghouls and Ghosts.

Man, I can go on and on...