Carmageddon (1) when the game crashes just as you are about to complete a very hard level you played for half an hour. You can't save during the level, of course.
Age of Empires, when you find out you'll have to restart the whole level you've been playing for the last two hours, just because the "corrupting save games" bug has hit you again. In the end, you become afraid to save a game during a AoE mission at all in fear of tainting your save games with corruption, and try to clear all the missions ironman mode, without saving in-between.
I also remember getting angry in TeamFortress Classic sometimes because either some people weren't interested in playing as a team, or some even just tried to destroy the gameplay of their teammates. But later I learned to mellow out and change server, if something like that happened.
Oh right, in TFC the cases where in a public server one team had many more (good) players and was trumping easily the other team, making the game boring for both teams. In such cases I always switched to the losing team to make it more interesting, but many didn't seem to be interested.
Sometimes when I saw that happening and no one (else) changed to the losing/smaller team, I might switch to the winning team (e.g. Blue) as well and write something like "Yeaaah, let's kill the Reds! They have nothing on us! Everyone, change to the Blue team, we'll beat the Red bastards for good!".
For some reason, my new Blue teammates didn't usually seem to appreciate that move and started bitching to me. What's the matter, I thought you liked the uneven gameplay? ;) Usually after that many people from the winning team were all of a sudden magically willing to even out the teams. Mission accomplished, game was interesting once again.
Post edited November 24, 2011 by timppu