I've got a few so I'll kick us off.

Outer Wilds

I listen to this one an awful lot, and from start to finish, which is pretty rare for me when it comes to soundtracks. The song '14.3 Billion Years' still gets me even today and the games main theme is one or the more memorable bits of gaming music I've ever encountered.

Return of the Obra Dinn

Atmosphere. The music goes an awful long way to setting a games atmosphere and this soundtrack is no different. I can't necessarily listen to this on repeat like Outer Wilds, but when I do listen to it I'm immediately catapulted back to being on that damn ship.

Tearaway

This one is just disgustingly charming in a way that only a game for a Media Molecule game could be.