How a game sounds is important for me. A good soundtrack not only makes a game memorable, but can really help you get "in the zone" when playing.
However, sometimes game music is just unbearable. This really started to happen in the 90's with CD-based systems introducing "real world" music into games. Which is a horrible idea as not everyone likes the same kind of music and eventually you end up playing something with music that you just can't stand.
Here are some examples of things that I couldn't stand.
From Animorphs: Shattered Reality (PS1)
Music from Animorphs: Shattered Reality - Place To Dwell
This was my face while playing:

From Buck Bumble (N64) :102:
I also never played F-Zero GX for more than a minute because I couldn't stand the music.
I'm sure some will disagree and will hate some of my favourite soundtracks too, but that's why game music should just be proper old chip-tune style game music.
What games can't you stand listening to?