lol my brother was playing some online game Age of Chivalry i think, and he was getting thouroughly whooped, he was backing up with this guy running at him sword waving, and my brother somehow pulled his crossbow out and shot the other in the head, just as the other was about to land the killing blow, thats more luck then funny, though i did laugh because my brother nearly had a heart attack
but myself (when i was 6-8, cant remember exactly) i was playing quake 3 i think, and i was playing capture the flag, and i was right near the enemys flag and i turned around seeing one of the enemys flying towards me (off a jump pad thing) and in a moment of panic i shot my rocket launcher (cause that was my fave gun) and it like hit the enemy and his bloody pieces flew at me, i laughed and was so very proud of myself