Thought there was a thread like this before, and some of these are very old, but...
HALO online (yes the first one), i was the gunner on the back of the warthog in that L shaped map, we had just captured the flag and were being chased by an enemy warthog...
i fired a rocket (from the turret on the jeep), it hit the front right wheel of the enemy jeep sending it into a barrel roll, killing all three occupants...
Pro Evolution Soccer 4, my brother and all his friends love this game, so one day a bunch of em are in the house and they challenge me to a winner stays on tournament... i beat every single one of them, i actually had to give up after i beat the final one...
The first time i used a tow cable on the snowspeeder to pull down an AT-AT in Star Wars: Battlefront/Battlefront 2... on co-op...
Playing Resident Evil 4 on Gamecube... one of the greatest games ever made imo...
Anywho... i'm backed into a corner, and a group of enemies are fast approaching... then i spot it... one of the guys is holding a stick of dynamite... just as he goes to throw it i fire, detonating it in his hand... killed like 8 guys with one bullet... yes i felt especially smug afterwards...
DOW: Soulstorm... As Space Marines, fighting the Ork's on their home map. Four and a half hours of bloody slaughter, slowly making my way across the map. When i won, i just sat there and took a breath or twenty...