Me, two stories, both in L4D
First, as the survivors we had a full 4 man lan game, going through Dead Air part 3, were in the parking garage at the terminal, not doing well, no kits and low ammo, I was down to pistols, we go up to the second level of the garage, "TANK!" and I think, "Oh Shit" like the 2 hicks that run over the zergling in the starcraft cutscenes, we start firing WHAM one guy down, we run back down to first level, car, WHAM 2 more bite the dust, now I know I'm screwed. I emptied my pistols again and again and it drops about 20 feet away, and I damn near pissed myself, but thats not all, I had 3 dead teammates by then so I limp all the way to the safe room, and almost got snagged by a smoker. Sickest Recovery Ever!
Second, 2vs2 versus mode, No Mercy, the Finale, I'm on infected with my more teamwork oriented friend whereas the survivors were the lone wolf types, they didn't pay too much attention or do much team work. I got the tank and was gonna start pounding after them, but I got glitched in the elevator shaft and lost it, next thing I know, respawn as a hunter, my buddy as a smoker, the guys go up the ladder and jump off the roof, the bots are still climbing the shaft, I jump one, smoker gets other it's perfect. And to top it off, theres a witch upstairs that kills one and the other died from commons. Awesome Tag-Team.