Suggested by me:

Some of the finest video game music to exist, through and through. Falk, James Landino, Andy Tunstall, Funk Fiction and Michael Staple are inspirations, some of whom I have had the honor of being friends with here and there.

Want to study fairly advanced jazz harmony? Tea With Ellie, or the entirety of Technology Tree. References for really dense yet clean production and mixes? Falk, James and Funk's sides in particular are godly. Just looking for insane grooves and riffs? Andy Tunstall absolutely kills it with Moon Mansion.

After the Sequel comprises a fairly significant part of the unofficial, scrambled-together VGM textbook that I self-studied from for years, and I don't think I'll ever fully graduate from it. I even played Tea With Ellie as part of my graduation performance!

Bless this soundtrack. Bless everyone on it. I'm always excited to see something new from the gang, especially when they join for some reunion parties.

Suggested by LordTentacle69:

I'll make a proper write-up soon, but in the meantime, the titular Lacrimosa of Dana theme is some of the absolute best, emotional, powerful, expressive orchestration I've heard in video games. Please, please listen to its opening variation if you have some time to spare.

Suggested by Midrulean:

Oh god, ranking a Sonic soundtrack above Mario feels like heresy. But I'm pretty confident about this; Sonic CD and Jet Set Radio were fairly influential to my own music, in a previous life. (tbc)

Suggested by me:

What can I say about Koji Kondo's Super Mario Bros. that hasn't already been said? It's insanely catchy and memorable, with an amazing 35-year-long legacy that's lent itself to being reimagined and transformed time and time again.

There's some interesting things here for a 1985 soundtrack, too. The Ground BGM has an interesting, atypical form structure of (roughly, minus repeats) ABCADCD before looping that kind of reminds me of some modern games' tendencies to split their music into sections that determine when they're played based on gameplay context.

It kind of breaks my heart that I will inevitably have to rank some soundtracks above this, but it's to be expected. I will make myself clear, though - this is the litmus test of soundtracks I truly hold dear to my heart one way or another.

Suggested by Squigglydot:

temporary position, comments tbd

Suggested by gyoza:

What SNES soundtracks do you think aged well? As far as games released before Mega Man X goes, I'm gravitated to F-Zero, Super Mario Kart, Star Fox and Plok, just to name a few.

I've worked with the SNES myself, and I think it's a tricky, but rewarding system to make the most out of - I think the games I've listed above nail it; either through clever sound design (including echo and panning); efficient, economic writing and arrangement to make sure that all the necessary details and depth are present with minimal polyphony use; or both.

I... don't really think Mega Man X is one of them. Please don't take this as me saying that I think Mega Man X is bad; it's me saying that for 1993, Mega Man X makes slightly clumsier use of its sound chip than its contemporaries. I'm thinking about the legendary Opening Stage theme, and how they could have just sampled a power chord or guitar in fifths to save a voice that could have gone into something that added a bit more depth to the arrangement; how adding echo to the drums in Zero's theme (and many others) only makes them sound weaker and muddier...

But I'm only getting started. On a sound chip with an already weak high end, the lead melody in Armored Armadillo gets a bit drowned out by the loud, active guitar arpeggios that are only really saved by their hard panning; the first thirty seconds of Boomer Kuwanger basically uses the same four-note polyphony as the NES games with much less deliberate sound design (you could port the song to the NES with very little lost in translation)...
And that's something I could say about the entire soundtrack to generalize, actually. It sounds not significantly better than the NES soundtracks, and makes significantly less impressive use of the sound chip present.

This I think also leads to some less interesting arrangements than could have existed otherwise. I've already mentioned the opening stage, but a heavy contrarian opinion I have is about Storm Eagle; it's a lot more boring than it deserves to be. When you're dedicating two channels of polyphony to have muted guitar strumming along to the same basic pattern as the bass, and the drums don't have nearly enough accentuation or fills to actually have anything interesting to say, a lot of probably intended energy is lost.

This isn't to say that I hate the soundtrack, because I'm sure I sound like I hate it right now. Its melodies and songwriting sense is spot-on; the songs that I think nail it, like Sigma Fortress 1, Sting Chameleon and the aforementioned Opening Stage are the ones I think give Mega Man X a well-deserved spot in renowned retro soundtracks.

Suggested by me:

I feel somewhat compelled to include a soundtrack I don't particularly enjoy from a game I think is otherwise quite good, for reference.

The Sony PlayStation's sound chip was basically an evolution of the SNES's, having so much of its charm but with increased capabilities, even without relying on CD audio. I think the entire Crash Bandicoot trilogy kind of squanders it, honestly - a lot of the melodic samples sound really tinny in a way that betrays the real strengths of the sound chip, and the whole soundtrack sounds sort of unbalanced, with percussion often being too overpowered by comparison.

It's a shame, because I don't dislike the compositions. I think Crash 2 has a lot of stronger, catchier music than the first game, but the issue is definitely in the production. In fact, the N. Sane Trilogy version actually addresses a lot of those issues, and I prefer its version of a lot of tracks. Turtle Woods gets a lot of much-needed power through the added guitars, the Warp Room's clavinet finally actually sounds like what it's supposed to sound like, even if the arrangement could still use some work, some tracks like Snow Go are basically new songs entirely in terms of feel...

But N. Sane Trilogy doesn't salvage everything in my book, and I don't think it really could have. A problem I have with the first game is that I felt like it relied too much on empty, fairly non-substantial riffs, and the same is the case for a lot of Crash 2's weaker tracks. Compare the regular version of Turtle Woods to the bonus version, for example, where the lead mallet percussions lack any real sense of melodic direction or contour whatsoever. For a series inspired by classic cartoons, it's just so weird to see music meander so much when those very cartoons, in my opinion, lived and died on snappy, witty, sometimes really cheesy but uncompromisingly strong, confident music. What happened?