My favorite fps achievement took place in Halo on the Xbox. We did the thing to play online and during an online ctf match I was on point with the sniper rifle. The match was tied up for flag captures and we were in a stalemate for a bit. The other team managed to get our flag and were running it back. As I'm in my sniper spot trying to line up the shot they all jumped at nearly the same time right into my sights. I take the shot and head shot every one of them... Except for the flag carrier because they apparently jumped just a tiny bit ahead of the others and dropped just enough to go under the bullet.

The entire lobby was going nuts over that last sniper shot. Even though we lost it was the talk of the match. The loss sucked but that shot was amazing. I quit playing for the day after that... No way was I going to top it so I left on a high.