Shantae and the Pirate's Curse had the best soundtrack ever for me.
Hyrule Warriors is a close second. They really did wonders with the Zelda music.
Smash Ultimate is third due to the sheer amount of great music from different franchises it has.
4th is Gokujou Parodious (Parodious Fantastic Journey in Europe), and the whole series by extension. They really made miracles with classical music there.
5th is Megaman 2. Almost all the tracks are great, but few can really match the greatness that is Wily's Castle Stage 1&2
6th is the original Super Mario Bros. Really only 4 tracks, but each one is fully ingrained into the brains of the gamers from the 80's - and beyond!
7th is Command&Conquer: Red Alert. Hell March alone warrants a spot on the list.
8th is Crazy Taxi, at least ir's original release. Ya! Ya! Ya! Ya! Ya!
9th was Burnout 3: Takedown. Really loved it's song selection
10th is Double Dragon for me. Great and varied music fitting for each stage, with the Mission one track really setting the tone for the game.

Honorable mentions: Fifa 98 RTWC only due to Song 2, Monkey Island's varied Caribbean music styles, Civilization IV, especially Baba Yetu, which is the first and only videogame song to win a Grammy

I'll probably change my mind in a few minutes, but here are 10 that I really quite like in no particular order:

1. Age of Empires - The second game was better, but the first one had an amazing soundtrack.
2. Chrono Trigger - Does a lot of kinds of music very well.
3. Final Fantasy VI - One of the more ambitious soundtracks out there.
4. Legend of Zelda: Ocarina of Time -
5. Legend of Zelda: Breath of the Wild - A very different soundtrack from the rest of the series, but by no means worse for it.
6. Mega Man 2 - Lots of great chiptunes.
7. Shadow of the Colossus - Lots of songs that make you feel intimidated, triumphant, or mournful.
8. Super Mario 64 - A bit sparser than ideal, but pretty much every tune is great for what it is.
9. Super Smash Bros Brawl - Deserves a lot of credit for turning the Smash series into a musical powerhouse.
10. Undertale - I really like the use of leitmotifs and overlapping themes in this soundtrack.

Paper Mario, Metroid Prime and Halo 2 have the most consistent OSTs I've ever heard.

In no order
KH series
Persona 3
Persona 5
Final fantasy 7
Detroit becomes human(I didnt actually play this game lol)
Super Mario Galaxy
Pokemon White 2
Pokemon Sapphire
The legend of Zelda Skyward sword
Xenoblade series

This lists probably changes a lot.
If I had to rank the top three it would be
Persona 5
Mario Galaxy
Final Fantasy 7

I find it hard to pick a top ten, but Donkey Kong Country 1, 2, and Tropical Freeze would all absolutely be up there, their music is just magnificent.

1. Chrono Trigger
2. Legend of Zelda: Ocarina of Time
3. Final Fantasy VI
4. Donkey Kong Country
5. Final Fantasy VII Remake
6. Final Fantasy X
7. Hollow Knight
8. Castlevania: Symphony of the Night
9. Nier Automata
10. Final Fantasy XII

Honorary:  Breath of the Wild, Suikoden II and III

Hard to choose and hard to decide an order. Not sure tbh, maybe Hollow Knight should've made the top 5. 
Thing is, my top 5 (and SOTN) are very much a huge part of my childhood, I had those songs playing all the time. 

Chrono Trigger: I learned to play almost the entire Chrono Trigger soundtrack on the piano, Yearning of Winds and Corridors of Time were always my favorite. Until recently I had this entire soundtrack on my ipod and played it everytime I went out to jog. 
DKC: Aquatic Ambience, Forest Interlude, Mining Melancholy and the theme in the levels filled with thorns, I dont recall the name. 
FFVI: Terra's Theme and Dancing Mad - to which I had that fixation with for some time.All of them were very much my favorites. 
OoT: Every song is really great, my favorite is I guess everyone's favorite: the Gerudo Valley theme. 
SOTN: Nocturne in the moonlight easily takes my #1 spot. 

FFVII Re is probably my favorite soundtrack of the current gen - tho its contested by Hollow Knight and Nier Automata, both which I put as background music almost in my every activity. FFX is a weird addition on my list because its a FF game im not particularly fond of, I find it a bit annoying, but the music is superb. To Zandarkand on the piano is just an absolute treat to play and to listen to, and Suketi Da Ne is not far behind. 

At times i've been thinking about trying a certain game I havent played or doesnt really catch my curiosity simply because Nobuo Uematsu is the composer. Granblue Fantasy and Hyperdimension Neptunia for example. 

Edited since I noticed I added FFVI twice by mistake.

i agree with this shiz right here,

ff7r has to be one of the greatest soundtrack of all time!

specially the underground music with the thugs lol R.I.P replay button!

1. Final Fantasy VII Remake

2. Final Fantasy XV (fcken yoko shimomura at her finest!)

3. Kingdom Hearts II (AGAIN YOKO HAHA!)

4. Gran Turismo 4 

5. Need for Speed: Most Wanted 2005

6. Driveclub

7. The Last of Us

8. Bloodborne

9. Dark Souls III

10. Witcher 3: Wild Hunt

I want to give an honorable mention to Rockband and Guitar Hero.  These games have amazing songs, but I somewhat feel like it's cheating to put them in my list.

10. Octopath Traveler

9. Suikoden

8. Blaster Master

7. Final Fantasy Tactics

6. Cadence of Hyrule

5. Castlevania

4. Metroid

Putting Final 3 in my next post....

3. Undertale

2. Katamari Damacy

1. Final Fantasy, the whole series (don't make me choose)
Here are a few great songs from a very long list of great songs:

FF4

FF6

FF7

FFX

I'm not sure what my top 10 would be (likely lots of FF and Persona) but I know for sure Nier Automata and Final Fantasy XV are my latest favs from this gen. Say what you want about FFXV with its mixed reviews, but the soundtrack was nothing short of amazing.