Does me dying of laughter count?
I was playing Medieval II: Total War, and I was attacking a rebel town with a new general. I decide to listen to his pre-battle speech, expecting the usual comments about how killing the rebels would be a blessing because it would get them away from the shrill whores they call wives, stuff like that.
Instead, the general launches into a clearly-not-at-all-prepared speech in which he forgets his lines, rambles about the weather and the food, and at one point realizes that yes, he's going into battle and it might not be a very nice experience. His soldiers clearly don't know what the fuck is going on, since they don't cheer once during the speech.
(spoiler alert: we win anyway)
Okay...actual death (or close enough, anyway). The Pope calls a crusade on Cairo, and I, being a good Catholic English King, decide to send my faction leader and a large army by ship. They draw closer and closer until, two turns away from landing in Egypt, the faction leader dies of supposedly-natural causes. This causes EVERY. SINGLE. UNIT in his army to desert on the next turn (despite still being on ships, and no I have no idea how they got away), which means I lost thousands of florins worth of soldiers and mercenaries, not to mention my faction leader, for absolutely no gain whatsoever. We never even freaking
landed in Egypt.