Suggest a game with a great soundtrack

Killer Instinct

Since no-one else is gonna mention it- Giana Sisters: Twisted Dreams.

And for some more popular(?) stuff:
Serious Sam Series.
Painkiller.
Before The Echo (though it is a rhythm game so it's to be expected :D ).
Hotline Miami Series.
Super Meat Boy.
Devil May Cry Series. (<- A bit of a loudness warning on the 3-rd one... ^_^' )
And too many anime games to mention all of them... But I can immediately think of Rabi-Ribi and the Hyperdimension Neptunia Series off the top of my head.

The Legend of Dragoon for the PS.

Audiosurf 1 and 2 = your mp3 collection <3

The Cat Lady The creator's friend basically gave him an entire album of rock music to use with no copyright fees.

Night in the Woods

Hotline Miami Obviously. Also check out Lone Survivor, which shares a composer.

The Danganronpa games

Anodyne If you like 16-bit.

Although some design choices are terrible, I believe Nier Automata has the best soundtrack when it comes to games, with the Witcher 3 coming in as a close second.

Bravely Default
Metal Gear Rising
Xenoblade Chronicles

• Witcher 3
• Nier: Automata
• Gravity Rush 1 & 2
• Hotline Miami 1 & 2
• Bayonetta
• Transistor
• Payday 1 & 2
• DOOM (2016)
• Horizon: Zero Dawn
• Yakuza 0

Mafia 2 and 3, doom, payday 2, tropico 4.

Life is Strange :)

Hotline Miami.
just listen to https://www.youtube.com/watch?v=NcM_JrdSJSU
and https://www.youtube.com/watch?v=mKEqIIn4pEQ

Remember Me

The Sexy Brutale has the best I've come across recently. It seems to be online here

Incidentally, there's a Twitch streamer who does a great job playing game music on request. I came across an interview with her; her improvisational skills are remarkable.

Child of Light has a pure and amazing soundtrack. The Hymn of Light for Chorus, Aurora's Theme, Bolmus Populi, awww <3
Ori and the blind forest also, of course. Especially this wonderful music. Everyone who has played the game knows this song, as it probably looped several times before finally succeeding this damn hard but incredible passage.

Grim Fandango
Brutal Legend ;)
Life is Strange - despite being horrible game in my opinion, has AMAZING soundtrack
Old Need for Speeds like Most Wanted and Underground 1&2 era. Also Crazy Taxi if you into driving games
And basically everything that Jesper Kyd laid his hands on. This man created some of the most iconic sounds for me, i would recommend Hitman 2 and Assassin's Creed 2 to hear some of his best stuff

Sorry, but I cannot choose just one!;)

(in no particular order)

1. Life is Strange
2. Submerged
3. Bioshock (the 3 tracks you got on CD with the CE version was nice as well)
4. Remember Me
5. Layers of Fear
6. Wasteland 2
7. Titan Quest
8. Alum
9. Icewind Dale
10. Doom and Doom 2

I could list more, but I don't want to go too overboard.;)

I'm gonna go for the less known options (because all AAA games have already been posted).

• Bit Trip Runner 2 (all the series has catchy music, but Runner 2 takes the cake)
• Uplink
• Thomas Was Alone
• Trauma Center series
• VVVVVV
• Super Hexagon
• Cave Story
• Before The Echo
• Fallout New Vegas
• Deus Ex
• Unreal
• XCOM Enemy Unknown
• Metal Slug series
• The Binding of Isaac (the original, not Rebirth whose soundtrack was a step down if you ask me)
• Ducktales (both the original and the Remastered)
• Mega Man series
• Wipeout series
• Quake
• Rez
• Jet Set Radio
• Bastion
• Rusty Hearts (unfortunately isn't available anymore, but you can find the soundtrack on YT)
• Super Smash Bros series

Journey to Silius
Curse of Monkey Island
Batman
Planescape: Torment
Guild Wars
Final Fantasy 6
Europa Universalis 4
The Witcher
Battletech
Cuphead

Should give you some variety!

Rebel Galaxy
Every single Tropico game. 2, 3 and 5 are the best.
Simcity 3 and 4
Startopia
Evil Genius
Civilization IV
Rome Total War
Rollercoaster Tycoon 3
Railroad Tycoon 3
Locomotion

Ori and the Blind Forest, Bastion, Cave Story, Guild Wars, Trine, RollerCoaster Tycoon, Robot Roller-Derby Disco Dodgeball, Assassin's Creed, Super Hexagon, VVVVVV.

Ancestors Legacy has a really cool soundtrack

Full soundtrack preview

Some I like in particular:

Tales of Maj'Eyal
Victor Vran
AQ3D
Oceanhorn
Aviary Attorney - Classical stuff. The game is a genuine piece of art!

https://store.steampowered.com/search/?snr=1_5_9__12&term=great+soundtrack

Basically the only game that ever made me care about its soundtrack and listen to the music outside of playing the game was Machinarium.