Skyrim soundtrack is the most memorable to me. To this day I'll listen to songs in loop while working, it helps center me. The atmosphere is great and I love Jeremy Soule Compositions, such and amazing composer!

HOMM3 hands down!
So many sleepless nights spent with it

Definitely Diablo 2 Tristram and Lord of Destruction theme. Matt Uelmen works simply carved their way into the deepest layer of my brain when I was a child. We sang these themes every time a LAN took place and D2 OST was just ramping up from someone's speakers.

For me, the absolute all time best soundtrack is The Elder Scrolls Online OST

Honorable Mentions:

Advent Rising
Age of Empires
Endless Ocean
Fable
Final Fantasy 7,8,9,10,13
Guild Wars 1,2
Heroes of Might and Magic 3,4,5
Horizon: Zero Dawn
Icewind Dale 1,2
Jade Empire
Mass Effect Trilogy
Neverwinter Nights 1,2
Star Wars: KotOR 1,2
Star Wars: Jedi Knight
Star Wars: Jedi Outcast
The Elder Scrolls: Morrowind, Oblivion, Skyrim
Tropico
Warcraft 2,3
World of Warcraft

Mass Effect Main Title Screen.

It just says "go into the world and explore"!

It's pretty hard to choose 'cause of the many years of gaming history and immeasurable work of the talented composers.
And even if I'd try than it would be either Tiny Toon Adventures: Buster's Hidden Treasure or Contra Hard Corps, both from the now dying giant Konami, both for Sega Mega Drive console.
Both can be listened without even playing game and sounds perfect even to this days.
Both evoke nice feelings and memories from the school years of my.
Listening to any of those would send the picture of the corespondent game moment to my brain, and that pictures was perfect - Konami knew how to make great games completed with a bombastic/atmospheric soundtrack back at the 90's, not so nowadays...that's sad.
Of course there also was that perfect metal ost of another Mega Drive game called Thunder Force IV which was and still is the greatest shoot'em up soundtrack of all times (no one could outdone Technosoft guys), but if I'd measure those three music albums than TFIV will be on the third place after two Konami masterpieces of the 90's.

Mass Effect - all 3 OST from original series are my faovrite, but one o them step out from the line, its the Mass Effect (1) - OST - and why? Its easy, it was the first one, also music is combinig all the best and especialy I like the atmosphere, which is going through all feelings (from dark tones to positive awaitings). Other ME OST are more dark, but it corespondents with the story.

So thats my choice. :)

Literally every track from FlatOut 2 is a masterpiece. Not sure it's a eligible choise cause all of those are not written for the game. But those rhyths of Papa Roach, FallOut Boy, Rob Rombie and many others gave me passion for rock and metal.
And remember kids - don't listen to the radio.

Witcher 3 + DLCs and Risk of Rain 2. Both are on my playlist whilst riding my motrocycle.

For me it's Dragon Quest VIII (specifically the versions with live orchestra) without a question. The overworld music alone is a masterpiece, but the way it contains many styles of classical music in different contexts in a way that sounds authentic is awesome. It gives a feeling of not being inspired by movie/game soundtracks but by actual classical music. Baroque in a king's castle, romanticism travelling the sea, modernism at an evil altar. Listening through the soundtrack recordings outside the game, they were even performed by the orchestra as longer "suites" then cut up into the sections that loop within the game, making it feel like a classical concert. Within the game, those "section/version switches" instead occur along with gameplay, like as you hit tresholds in moving further into a dungeon.

One of my favourite examples of the style shifts is how the boss music starts out as just a more "epic" version of the jaunty normal battle music, but when you get to more serious fights and expect it to escalate further, it instead takes a 90 degree turn into slowly creeping and dissonance (and then THAT is what's dialled to 11 with bombast later). As if to show that this isn't just fighting a more mighty monster than normal, this is a fight against something truly evil and corrupted.

Lord of the Rings Battle for Middle Earth Evil Campaign Song

it took a lot of time to this menu music

I particularly enjoyed the OST for Tom Clancy's Splinter Cell: Chaos Theory (2005) by Amon Tobin. Has to be the most perfect link to the game's progression I've ever encountered. There is simply no atmosphere to the game without it, the music is dark, powerful, upbeat when it needs to be, and very well merged with the Japanese settings in the game. Basically most of the suspense, and the call for action or stealth accordingly; comes from Tobin's music.

The guy's live act is beastly as well, a whole experience. I remember seeing him once and he managed to mix "el cargo" into his set, which is one of the tracks included in the OST. Truly it is a masterpiece, and can be listened to as ambient, workout music or even for studying, and it gives the same sense of varying chill/urgency as if you were playing the game. Highly recommended.

By the way, I also love the HOMM3 soundtrack, shaped my childhood and it's just so well done.

I grew up playing the NFS games. I recently started NFSMW 2005 again and I thoroughly enjoy the soundtrack. So, probably Need for Speed: Most Wanted (2005) & Need for Speed: Underground 2 (2003) soundtracks.

Weight of the World from NieR:Automata
by Keiichi Okabe

It plays during end credits and hits like a rock. It's adding immeasurably to the catharsis you experience at that precise moment

The old music from the C64 games are still very attractive, even though technically they aren't good anymore.

The music of Monty on the Run and Turrican and Turrican II still are my favorites.