Best game OST?

Surprised no one's said Perfect Dark. <3

Mass Effect 3 or Max Payne 3. I enjoyed them at least.

Both Payday games have a good soundtrack, I liked them.

Genuinely surprised someone didn't say almost every Zelda and Mega Man game ever.

DIRT 2 - Limbo

Half Life
Arcanum
Bastion

Jet Set Radio
Heroes of Might and Magic III
Hotline Miami
Donkey Kong Country

Castlevania: Curse of Darkness.
For me, this game has the best soundtrack on castlevania series.

Crazy Taxi, Sega Dreamcast (DC) version. The Steam version has a different set of soundtracks that don't resemble the original DC one.

Dwarf Fortress

Silent Hill 2.

Almost every Castlevania Soundtrack.

Almost every Super Robot Wars soundtrack.

I personally love Skullgirls' soundtrack as well.

i'm shocked no one said Shadow of the Colossus

Everyone else had listed my favourite OSTs, except:
-Warlords Battlecry 3
-Dota 2
-The Binding Of Isaac
-Terraria
-GTA
-Ballpoint Universe
-Antichamber (lol)

Trine 2.

It's the OST that I loved the most, it was the most memorable one, the best one. Terrific track.
Other OSTs that are worth mentioning would be:

Robot Roller-Derby Disco Dodgeball
Just Cause 2
The Elder Scrolls V: Skyrim
Left 4 Dead 2
Portal
Sid Meyer's Civilization V
Tomb Raider (2013)
Team Fortress 2
Battlefield 1942
Mario
Bastion

Sang-Froid - Tales of Werewolves

https://www.youtube.com/watch?v=2KHC_JKAqy4&list=PLNgZ3ypf3KeYK6AXxKR7Y6p-EU0NW0S8O

One of the best:
Guilty Gear XX Soundtrack

Rock-group Poets of fall. Soundtrack for Max Payne 1-2 and Alan Wake.

i like bastion and braid

The legend of zelda ... Sagas...

Most of the Total War games have some really good music.

The ost of Braid its amazing!

To the Moon

Devil may cry 4 - shall never surrender
Dishonored - drunken whaler
X Blades - (Metaphysics) - Golden Despite
The Fall Last Days of Gaia Main manu theme

System Shock 2

Morrowind, Bastion, and The Legend of Zelda are my personal favorites