Dont buy a new monitor before you try this!
http://entechtaiwan.net/files/pstrip.exe
It's excellent. You can create hotkeys for brightness, gamma or enything else that is windows/color related, so you can correct your screen while in games/programs, without going in menus! Furthermore, if your monitor has a dominant color, no problem.
Even if your monitor is fine, I still recomend that you download this great utility. I found that most games have different gamma settings, so you can do your own presets for each game.