ImADot's suggestion might help you to get your monitor settings right. Remember to start from scratch, setting both your monitor and video card settings to their defaults. Then adjust only the monitor until you either are satisfied or you reach the limits, forcing you to continue in the video card settings. Insufficient brightness and contrast settings in an older monitor often are symptoms of a nearing end.
IMO you'd better leave all the settings you mentioned to their defaults and use AH video settings instead. Anti aliasing smoothens slanted sawtooth lines to look less jagged by adding in-between hues between darker and lighter "teeth". Anisotrophic filtering adjusts the surface textures according to your suggested viewing point, kind of correcting the perspective of subsequent tiles seamless, thus clearing the view to far. Trilinear filtering is somewhat related to that.
Just leave those to default and do the adjusting in AH, starting from zero and working your way to the point you feel like you're sacrificing your playability to eye candy. Read
Waffle's tips in the Tech support section.