tburger: 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.

Klumpen0815: First time meeting a Schattenläufer in Gothic 1.
(Shadowbeast in the English version, although it means "shadow walker")

I just strolled through the woods and... well you all know what happens then. No chance to run from these.

Much later in the game when I was a mighty warrior, I hunted down and slaughtered every single one of them in the game, tore their horn out, skinned them etc.. and sold their parts for a good price. :D