Hmm, probably that time I was playing Gears 2 with a few mates (one of which was Dexter Manning, AKA one of the guys who makes Sanity Not Included, its a long story about how I got him on my friends list...)
Anyhow, Dex was fighting me and two others, and he just raped us completely solo despite the odds, that everyone was using shotguns, and that we were all pretty decent players ourselves.
Oh, and on a somewhat related note, a few weeks later (shortly before he removed me from his friends list due to me going on holiday) we were filming for Call of Dover (a CoD WaW machinima) and 2 of us were running in circles around Dex. Annoyed, he fired a single warning shot, which killed both of us, and one guy who was watching in the background. Lulz were had that day.