ok let me tackle this. I'm going to just post some of my favorite songs, following in the pattern of one-per-composer. Not even going to attempt to rank them or be complete in this because it would just hurt me.
Yasunori Mitsuda - Chrono Trigger, "To Far Away Times"
Starting off with possibly the most perfect song ever composed? I just love this song so much. It's the icing on the cake that is one of the best soundtracks for any game or, really, any medium. Even though this soundtrack put Mitsuda in the hospital, I feel like I can honor his hard work by listening to it basically every week [strike]until the end of time[/strike] to far away times.
Koji Kondo - Super Mario 64, "Dire, Dire Docks"
Kondo has composed some of the most iconic game music of all time, but I think this is the best thing he ever did. Not as ubiquitous as Ground Theme and not as iconic as the Zelda theme, but the beauty of this piece is just so uniquely beautiful.
Nobuo Uematsu - Final Fantasy VI, "Terra's Theme"
Beautiful. I debated between this and the FFV Main Theme, but there's just a pain and resonance in this composition that I can't pass up.
Yasunori Nishiki - Octopath Traveler, "Decisive Battle II"
A relative newcomer to the VGM world, Nishiki kinda came out of nowhere and then dropped the hottest video game soundtrack of the entire decade. Octopath has possibly the best battle music the genre has ever seen, and that's not even to mention the amazing town and environment themes he composed for the game as well.
David Wise - Donkey Kong Country 2, "Stickerbrush Symphony"
This song deserves every ounce of praise it has ever gotten. It is impossible to overrate this song.
Hip Tanaka - Dr. Mario, "Chill"
I knew I needed to include Tanaka in this post because of how influential he is. His work is so foundational for the sound of Nintendo music in general. The thing is, I had a hard time picking an actual song, because most of what Tanaka composed himself was iterated upon and improved down the line. But those future composers who built on Tanaka's work were standing on the shoulders of a giant.
Kazumi Totaka - Animal Crossing, "Title"
Totaka is so weird and so fun. His work on Animal Crossing defined the entire Animal Crossing series with his work on the GameCube title, in a way that runs deeper than just the compositions themselves, I think.
Jake Kaufmann - Shovel Knight, "La Danse Macabre"
The more I listen to this piece, the more I think it's basically the most perfect up-tempo VGM ever written. The melody is unassailable. The arrangement is perfect. The beat is blood-pumping. The harmonies are exquisite. There is nothing wrong with this music.
Yoko Shimomura - Super Mario RPG, "The Road is Full of Dangers"
I realize I'm an outlier when it comes to Yoko Shimomura, as most people first associate her with Street Fighter 2. But entirely due to nostalgia, my associative soundtrack with her name is Super Mario RPG. Interestingly enough, I had a hard time picking out one song from the OST, because I think that score is more than the sum of its parts. I landed on this piece, though, as one that I particularly love and wanted to share.
Smattering of tracks I love from games I haven't mentioned yet and still want to mention:
Mario Kart 64 - Staff Roll
Mega Man 2 - Wily Castle 2
Mega Man 5 - Charge Man
Celeste - Scattered and Lost
Ocarina of Time - Hyrule Field
Majora's Mask - Stone Tower Temple
Twilight Princess - Hyrule Field
Super Metroid - Maridia
Super Mario Kart - Credits
Chrono Cross - Radical Dreamers/Unstolen Jewel
man, so many more, idk, I need to stop