What a fantastic idea for a discussion, Luke, and some really excellent choices (well-reasoned, too). Thanks for all of the effort that went into this one. I echo the sentiments about making this a regular thing if possible. Maybe bring in the whole team for their own personal favourite track / OST? And whilst I know this is ostensibly an Xbox-related website, don't feel beholden to it in any follow-ups.
Anyway, here's my completely subjective list to add to the group. I am not limiting myself to time period or platform but will try to keep the number relatively low (hopefully).
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Halo: Reach, start to finish, is probably my favourite offering from Marty O'Donnell - and whoever mentioned
ODST for the ambient section is bang on the money. Sit in a darkened room, put that CD in the stereo and
feel transported to New Mombasa in the 'Rain'.
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Sonic may have had his ups and downs (both literally and figuratively) but the one thing that has been almost unanimously agreed upon is that the music is, by and large, fantastic. Toss up between
Sonic 2,
Sonic 3 & Knuckles, and
Sonic Mania for which is the 'best' overall. (Honorable mention to
Generations for all of the - mostly - brilliant remixes of classics).
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Saints Row the Third and
IV make absolutely stellar use of their licensed soundtracks - plus, with the in-built playlist option, they're also (somewhat) customisable to your personal tastes too!
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Was
Terraria ever in the running for the Chiptune category? Because if not, I'm dreadfully sorry but you might need to go to a doctor and get your ears checked.
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Bastion is so good but because you've already mentioned it I'd like to signal boost
Transistor. It gets a little overshadowed by its older and youngest siblings which I think is a shame because It. Is. Beautiful. Shout out to the bonus track that wasn't even in the original release but is absolutely essential listening:
She Shines~~~
Command & Conquer. Frank Klepacki, utter genius.
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Skyrim.
I own the 4 disc collection (signed by Jeremy Soule). I have listened to it in its entirety multiple times. Enough said.
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MASS EFFECT TRILOGY!I'd apologise for the emphasis but I don't want to. The music and gameplay in all three combined perfectly into my all-time favourite experiences with the medium. The only thing that comes even close to matching Suicide Mission (and the level it's in), for example, is Halo 3's Warthog Run.