I know this has probably been done before but I'm doing it anyway!!!
My top 5....: 1.MW2; climbed to the roof at highrise and threw a semtex across the map and stuck my friend who was next to the opposite building!!! 2.MW2; Aphgan or how ever you spell it, I was sitting behind a bush and it was me vs. 2 other people and they both came and i ran out and sot one and knifed the other!!! 3.MW2; Highrise again and I ran backwards and jumped of the edge and threw a throwing knife and got someone right in the head who was going to kill me!!! 4.MW2; Estate, and I was on top of the green house playing no radar and two people came up the stairs and into the greenhouse and i got one with a claymore and the other with a flashbang and a throwing knife, game winner to!!! 5.CoD Black Ops Zombies; Pentagon, and someone was down at the complete other side of the map at level 10 and i had to run and kill 20 or 30 something zombies until i got to him and i was alredy hit one and right when i was about to heal him he died and a zombie then killed me. So it wasn't the best thing ever but was still pretty epic!!!
See if you can top thede kills which most should be able to do!!!