two things usually drive me nuts in most games, lack of good AA and screen tearing.
I don't mind muddy visuals sometimes, I usually turn off ambient occulsion because it really doesn't do that much for me, having AA turned up as much as possible and forcing Vsync on my games is a must since screen tearing completely destroys all immersion for me.
That said if I can handle the game fully I will crank it all up to max, sometimes if it's an older game I'll make use of Nvidia's DSR when possible.
I agree with your part about flickering shadows, that tends to bother me a lot of the time, I also dislike low res shadows that appear blocky as hell.
Mankind, in its arrogance and self-delusion, must believe they are the mirrors to God in both their image and their power. If something shatters that mirror, then it must be totally destroyed.
