Do you use always the original soundtrack?

[Lemnear]

yet another question, always for my curiosity.
There are games where you use a personal playlist instead of the original soundtrack? Which are? and which music?

[cfx]

There's sort of two different categories of this:

1. Games where there is a choice of soundtrack, but it's still a fixed pool of music. This would be games like the Raiden x Mikado shmups, where you can select song remixes, or any game that has an arranged soundtrack as well as an arcade original, or a lot of JRPGs that have DLC music that is generally music from earlier games in the series, as is the case now with Persona and all of the Atelier games.
2. Games where you can use your own music that can be anything you want. On Playstation, this was done in some number of PS3 games because the console itself had some kind of OS support for custom music that is missing in the PS4; I don't know about the PS5.

My answer is a bit different for the different categories. Games that come with arranged soundtracks I will use those if I prefer them, or I might use all choices depending on my mood at the time when I like all choices for different reasons, which I've done lately with the M2 ShotTriggers Mahou Daisakusen as an example.

In the other cases, I would favor using the original music because I consider it part of the game designers/developers' vision for the game. However, If I strongly dislike that music I'm fine with replacing it because in that case the original music lessens the experience for me or in many cases makes it where I won't play the game at all. Given games that have that type of support generally do let you change things on a song by song basis, I can change only parts I dislike and leave the rest alone.

A PS3 example that comes to mind is Wipeout HD Fury. I tend to dislike the music in all of the Wipeout games except the very first one on PS1. I have that game, and it's one that uses CD audio, so I used its music in the PS3 game. It's not the original music but as it's still music from a game in the same series, it feels like it still fits within the aesthetics of the game. I halso have the PS4 remake of that Wipeout, and it's unfortunate it no longer has that feature.

If the upcoming Persona 3 Reload has the DLC music from earlier games like Atlus has been doing, I'll be replacing parts of that soundtrack for sure so I don't have to hear rap that I can't stand. That feature if it's there and that the Japanese audio is included would be my primary two reasons for getting that version of the game over just sticking with the PS2 original.

[evil_ash_xero]

Always use the original OST.

Unless you're talking about games where they allow you to pick an alternate soundtrack or remixes.
Sometimes I'll do those. But I'm not pumping out Slayer to anything.