I couldn't do only 5, so I decided to do a top 15, because there was about 12 tracks that instantly came to mind. Also, I won't be ranking them, even though normally I would spend half the day trying to do so. I simply don't have that time.
I will just say that, normally, the tracks I think about the most are Wish of the Princess, Metroid Prime Title Screen Intro Theme, Lost Kingdom Forgotten Isle 2, Astral Observatory, Final Hours, and Heavy Price Paid - so take that as you will.
Paper Mario 64 - Wish of the Princess
This is one of the most strangely emotional tracks in a video game. The moment in which this is played is epic, heartfelt, and somewhat depressing, yet it's the music that helps sum up the scene so well. I don't think Paper Mario 64 did the best job of incorporating the dual narrative idea - but Twink rising up, and Peach basically saving Mario's ass, is surely one of the most memorable parts of the game, in large part because of this track. The (fanmade?) orchestral version is also amazing. Yet another OST where, like Metroid Prime, I could make most of this list Paper Mario 64 tracks, but I'm not really sure how to rank the tracks after this, so I'll just let this represent the game.
Metroid Prime - Title Screen Intro Theme
If I really wanted to, if I really, really wanted to, I could make a good 1/3rd of this top 15 Metroid Prime music. But, I'll spare you guys today. Admittedly, it's probably not fair to not include more Prime tracks, the other tracks definitely belong here. But this title theme represents the game so well, I think it can stand as it's own on this list to represent the entire game. Sunken Frigate, the 2nd Title Theme (how crazy is it that two of some of the best tracks of all time in gaming are just title theme tracks that most players will probably skip through?), Parasite Queen, Ridley, Phenandra Drifts (obviously)
Okami - Theme of Kaguya
I don't think much of Okami's soundtrack. It's not bad - if anything, it ranges from decent to pretty good. It probably averages out to around a 6.5. It's just, the way the game uses it's themes, a lot of them end up somewhat immemorable, samey, even at times kind of obnoxious. It's partially why my favorite themes are the ones that are both rarely used, and represent a more quiet sadness. Theme of Kaguya does this very well, making for a lovely track. It's also worth mentioning Cave of Nagi as one of the best tracks I've heard in a game - which goes for a similar tone, but with a more spacey vibe to it. It wouldn't be out of place in a Japanese-themed Galaxy level. Speaking of ...
Super Mario Odyssey - Bowser's Castle (Kingdom)
So unexpected and breathtaking - a great surprise in a game that already has one of the more consistent OSTs out there. I love how it doesn't focus on being epic, it's soothing, thought-provoking and mindful of the fact that the player will be hearing this theme for a long period of time (and has probably heard countless "epic" tracks in prior Bowser-themed levels). Yet despite this, it still has one of the coolest climaxes in a game track ever. Truly masterful.
Super Mario Odyssey - Forgotten Isle 2 (Lost Kingdom)
How can a song be so catchy and melodic and still make you want to cry? It's like a depressing Donkey Kong Country track. I have to ask, is this the best game track ever? It just might be.
Halo 2 - Heavy Price Paid
Though I haven't finished a replay yet, listening to a decent chunk of the OSTs, and skimming through some select songs, I think Halo 2 probably has the most consistent Halo OST. It's in that interesting area where, it still does have a few remade tracks from Halo CE, but the fact that it's a sequel - one that is quite a bit different in it's appeal from the original might I add - also forced the need for a lot of new tracks. It's not like 3 where so much of the OST is just remixes, or ODST and Reach where the OSTs are pretty good, but there's a couple tracks which are the clear standouts. 2 is just consistent back to back, and it helps that when it does tap into Halo 1's pool of songs, you end up getting the best remakes to date (Halo Mjolnir Mix theme, and especially Heretic#Hero).
As for Heavy Price Paid specifically .... it's odd, for most of this year I've consistently looked back on it specifically as one of my favorite game tracks of all time, a top tier choice. But everytime I hear it, I somehow think to myself "Man, I really underrate this track". Like it's brilliance is rediscovered with each listen.
Halo CE/Halo 3 - On A Pale Horse/Behold A Pale Horse
I'm not really sure whether to include the Halo CE On A Pale Horse original version, or the Halo 3 Behold A Pale Horse version. I think Halo 3's might have the slight edge, but it also has a lot of other different tracks spliced onto the end of the "On A Pale Horse" section, so it's harder to use as an example. It's more full and the choir adds a lot. That being said, while the "fullness" and three-dimensionality of the track makes it more immersive, I do feel like a little bit of the winter-aesthetic (and yes I would describe it as such because the song does such a good job of conjuring up such images) the original version had is lost when you add in the extra complexities and don't focus specifically. Maybe a little bit of the feelings of loneliness too? Less sure on that front. Either way, whichever version you choose, amazing track.
Phoenix Wright: Ace Attorney - Pursuit
I've been playing the Ace Attorney games and just by going through the first two, I can tell this series will end up having one of the most consistent soundtracks game-to-game of all time. The first two stunned me, seriously, I cannot believe how good the music is in these games. Every track is instantly mesmerizing the moment you hear the first second of music, even though most of them are only 35-45 second loops. Talk about baiting the audience's attention and reeling them in for more.
Phoenix Wright: Ace Attorney - Justice for All - Psyche Lock
Definitely could make it into the top 7 or so. I love the oriental vibe much of the JFA soundtrack has. It's so different from the first game but so amazing.
Final Fantasy VIII - The Man with the Machine Gun
Name a more fun, cooler battle. I'll wait. I'm not memeing. So unexpected and brilliant.
Majora's Mask - Astral Observatory
I kind of go back and forth about which track is the king of Majora's Mask's OST - this one, or Final Hours. I think this is one I think about more, because the spacey-yet-catchy motif it's going for is so up my alley, almost like a calling card. But Final Hours is just an immediate gut punch whenever you listen to it. It's a tie! .... I think.
Majora's Mask - Final Hours Extend w/ Bells & Earthquake
It's a fantastic track made even better by the in-game sound effects.
Megaman 2 - Bubbleman Theme
I love how strangely melancholic this theme is. It has no reason to be so, yet it is. The first track many people will hear in Megaman 2, is also the game's best track, and it has pretty good contenders to boot!
Devil May Cry 4 - The Idol of the Time and Space
There's a huge list of tracks from the DMC games that could, should, and do belong here, but aren't. That being said, this might be the best track of the franchise? It incorporates how I feel conceptually about Fortuna so well - you can visualize it clearly. Old ass secluded, relatively peaceful city with a mournful aura underneath. It makes you wish the city levels were a bigger highlight in a game that could really use more highlights in general.
Dark Souls - Gwyn, Lord of Cinder
Probably the most memorable final boss theme in games for me, or at least one of the more impactful. I don't know how much I thought of it at the time, aside from it just being very nice and fitting, but thinking back on it now it really is the perfect track. It's like a ballet, with the more rapid movements feeling despairing, intense, and downright violent - despite so much restraint from the composer.
Also - shoutout to my homie, Serpent Trench. Best standalone FFVI track*
*as of yet
and Astral Chain probably deserves a mention somewhere, one of the best new original OSTs on a Switch game I've played.
