I don't think anything's wrong with my monitor, because in regular oblivion when I use darker dungeons / nights, everything DOES get extremely dark.
Also, in Starcraft II, I had to turn up the gamma significantly to be able to see the terrain through fog, so there's another thing where it's dark on my monitor...
I'm thinking it's some sort of glitch with the game, unless all of the early on dungeons are bright enough to see in (starting and level 1-7 area?). Anyone got recommendations for this?
Oh also, when I set the gamma on my monitor itself to 0, I can still see, it just gets a little darker.