Planty of hard moments in games:
Fade to Black - jumping over moving forcefields in a passage (you could see them only wearing some kind of glasses)
Wing Commander 3 - mission with Skipper Missile and of course final mission (I cheated in this one)
Starlancer - last mission with rescuing Steiner. I was really frustrated about this one. When I was swearing AGAIN my wife asked me with her calm voice: why are you playing sth that instead giving you fun and relaxation gives you only bad nerves...Wrrr
Shadow of the Horned Rat - the first 'serious' mission with orcs when they hold Carlson's Family.