I feel as though soundtracks from the system are rarely discussed in VGM circles, so I am bringing it up. I'd like to hear what soundtracks you find compelling from the console. Go!

An initial pick to get the ball rolling:
Pokemon Red/Blue/Yellow
This is, I feel one of the true underdog soundtracks in game music history. Each and every track, of which there are 45, have memorable tunes with often stellar baroque-esque counterpoint which both complements and enhances the melodies. With the echo effect, the music gains a bit of ... fluffiness/levity that its predecessor lacked in a transition to a crisper, sharper sound. Junichi Masuda's work is one I constantly come back to to put me in a good mood in its bouncy and catchy atmospheres. Hands down one of my favorite Nintendo works!

Nice one, thanks for posting this. I have zero experience with the systems' music myself so will be looking forward to seeing what people post.

I think I might eventually try running polls for some of the other platforms (NES-SMS, SNES, Genesis).

Warlocked
Super Mario Land 2: 6 Golden Coins
CastleVania II: Belmont's Revenge
The Legend of Zelda Oracle of Ages/Seasons
Wario Land II
Kirby's Dreamland 2
Crystalis (The soundtrack is actually different from the NES one)
Teenage Mutant Ninja Turtles: Fall of the Foot Clan
Final Fantasy Adventure

Your right GB/GBC doesn't really get enough love. Those are my faves off the top of my head. Honestly I think my choices are pretty pedestrian, I think that a lot of these have some of the most well polished tracks in its library.

Mega Man: Dr Wily's Revenge (better than the NES score IMO)
Mega Man V (the game itself is overrated IMO)
Castlevania II: Belmont's Revenge (fracking fantastic and the game's amazing too)
Kirby's Dream Land
Metroid II: Return of Samus (this thing gets next to no love... and I'm not a big ambient score guy)
DuckTales
Super Mario Land 2: Six Golden Coins

and while it's not at the top of my list I'm going to mention:

Mega Man Xtreme / Xtreme 2 since it got released last year

Pokemon Card GB / Pokemon Trading Card Game

I cannot say enough wonderful things about this game's soundtrack.  I absolutely adore it.

Another shout-out to Mega Man V, and even Mega Man II, although the latter is an acquired taste.
It sounds VERY different from the other games, and not really Mega Man-esque, but I'm quite fond of it.

And, as always, you can't go wrong with first party titles, especially the Mario and Zelda games.

Actually, I kind of do like Mega Man II's soundtrack. I think there is some decent composition in there... it's just buried under some bad sound programming.

I grew up with the GB, and my love of VGM started there.

Here's a few great ones:

Castlevania: The Adventure
Castlevania II: Belmont's Revenge
Bionic Commando
Final Fantasy Adventure (aka Seiken Densetsu)
Mega Man I, II, III, IV, V
Kirby's Dreamland 1&2
Metroid II
Faceball 2000

Been away from the post for a while, I'm surprised no one mentioned Jonne Valtonen's experimentally invigorating work [for the system] on Project S-11 and Jake 'Virt' Kaufman's Shantae soundtrack. But, they are relatively obscure works on a pretty unexplored system for music in any case.

I'm really happy someone mentioned Final Fantasy Adventure . RPGFan's Ramza turned me onto that title, it's a gem, fantastic early Uematsu- I prefer it to his work Final Fantasy I-III.

Adam- I think running a continuous poll by system would be really helpful to get a sense of the landscape for each console, I don't think it's something that's been done largely elsewhere. I would be really grateful for its existence!

Uh, Seiken Densetsu 1 is pure Kenji Ito, aside its use of the chocobo theme.

GB is my favourite system for chip music.
Zelda: Links Awakening (probably my favourite Zelda soundtrack, loving all the different dungeon tunes, EXCELLENT use of the GB's dynamic range)
Seiken Densetsu 1 (some ingenious synth work in there, the stereo panning and synth phasing in the second world map theme are one of a kind)
Metroid II (crazy how efficient such simple ambient sounds can be, been a fan of Yoshitomi since)
Donkey Kong Land 1 (unlike its sequels this one had plenty new original tracks by Wise and Norgate that are really well done)
Mario Tennis GBC (lovely synth and noise channel work, some of the fullest sounding GB pieces)

Oh, man... just realized my mistake. Final Fantasy Legend AKA SaGa I is the title I intended. I've a lot of GB listening to catch up on. I've never actually listened all the way through Link's Awakening OST! Does anyone have opinions on Lufia: The Legend Returns or Megami Tensei: Last Bible I or II?