So, I've been thinking about this for a while now, how many soundtracks have I missed listening to because the game is supposed to be really bad?  I know in particular the Sonic games after Sonic Adventure 2 I haven't heard any of them, but if the sound team were the same they could be good but I have no idea. 

An example I do know about would be Silent Hill 4 having a great soundtrack despite the game being a huge letdown.

I would definitely check out Sonic Heroes after SA2. Kind of a lighter rock and it ditches the rap/jazzy parts of SA2, but still has all the earmarks of classic Jun Senoue on it. I've been slacking, but of the newer Sonic stuff I've heard I really liked Sonic Colors.

Unlimited Saga is probably my favorite Hamauzu soundtrack overall, but the game...ew!

Guilty Gear Isuka is a terrible game in the series, but the soundtrack is legit.

People crap on Megaman X5, but I thought it was okay. It's my favorite X soundtrack by a longshot. Similar thoughts on Megaman 6 (the game) and the soundtrack can definitely hang with 2.

My favorite example of a terrible game with great music is Tomorrow Never Dies (PSX). The game was unplayable garbage, but it has some of the best arrangements of James Bond music I've ever heard.

An even more infamous example is, of course, Cheetahmen II: https://www.youtube.com/watch?v=BkmbbZZOgKg

I replayed Mega Man X5 last year because of what you're referencing. I hadn't played the game for a few years and I just kind of started to write it off as "crap" because it's the start of the franchise's slide in quality. Yeah, it's not as good as X4 and it does have some problems that exacerbate my relationship with it but it's not bad and may be a little above average when I'm honest about it.

Now if you want to talk bad games with good soundtracks I'd probably go with X6 and X7... but while X7's soundtrack has some good tracks overall the thing is a mess. At that point they couldn't keep the game's problems from creeping over into the music.

As for other games Battle Arena Toshinden's music is that game's best feature now that the game has been beaten down by time and while I don't really have a thing for it the music is probably the only thing Samurai Legend Musashi should be remembered for. I tried replaying that and I wanted my damn $7.50 back... give me Brave Fencer over it anyday man! I have no clue how I put up with Samurai Legend back in the day....

That is scary...I was going to mention Toshinden too, but I deleted what I had written (mostly because my time spent with the game was minimal). I bought a cheap copy of the first game just for the redbook, but playing the game only yielded some minor hilarity. Hard to believe it was considered a major early Playstation release. The soundtrack for Toshinden 2 is probably my favorite non-Capcom, non-Arc, non-SNK fighting game soundtrack.

On that note, Fighting Vipers always looked uninspired to me, but I loved the first game's soundtrack.

I haven't played it, but Silver Surfer

It's not really a *bad* game (IMO) but what about Mega Man X Command Mission?

I'll be the first to admit I'm not a big fan of Shinya Okada (his stuff on X7 and X8 just bugs me...) but I do have kind of thing for this soundtrack for some reason.

I'll freely admit that a RPG wasn't really what the series needed at the time but I've played a lot worse and uninspired.

Good soundtracks to bad games......I heard Sonic 06 was like that.

I've read reviews of Madara and it doesn't seem like it's worth attempting to play, but the music is much more accessible.

One of the track in Adventures of Bayou Billy is among the best in Konami's history while the game is not fun at all.

I tried out Ys III and Brandish and thought they were terrible, but I can't function properly without the music. I heard that Ys is weirdo weird to play what with having to bump into enemies (like Hydlide), but I can't imagine being alive and not knowing the harmonies of Ys.

Oh, and I can't forget about Stack-Up (like it's something people know about). If there's anything fun about that game, then it happened in secret and has been lost to humanity. But that arrangement on Game Music Graffiti is nice.

One that always comes to mind is Sonic R.

I've tried to play this game ever since I got it for my Saturn, probably around the time it came out and everytime, it has failed to adapt to my sensibilities. It's just terrible. Music by Jacques is fantastic though, almost too good for that all-around ugly game. Only redeeming quality is the redbook audio, really.

I do remember it got really good reviews when it came out. Probably because everyone was so starved for domestic Saturn games and this was one of the only ones that had Sonic in it. Safe to say, Mario won that round. The music is an acquired taste, but it has grown on me over the years. It has its niche.

On that note, while I wouldn't call Sonic Lost World "bad" (demo seemed uninspired at worst and the consensus is more along the lines of fairly average), the music really surprised me. Lots of guitars/saxophones and it feels like a lot of live band performances. One of the best soundtracks I've heard from the last 5-10 years of VGM-dom or so. Every stage theme is golden. I would probably pick the game up cheap and tolerate it for the music.

Yup on pretty much all of these. Ys seems to really feature a sense of growth, but it seems like they all revolve around level grinding. Ys III could have been great in a Zelda II kind of way, but the grinding and the funky hit detection hurt it. Dat music though...

For Bayou Billy, the 1st/3rd stage BGM was basically the highlight of the game. Worth the $2-$3 the cart goes for nowadays though. But I would have cried if I had spent $50 that one back in the day.