Everytime in MW2, on S&D, when my group does riot shields only.
I'm crap at riotshielding, but I got a great one. Me and some enemy sniper are the last alive on scrapyard. We end up in a duel by the ATC tower. He keeps trying to knife me and missing, and then starts no-scoping me with his intervention. He hits me once or twice, but not enough to kill me.
Then, he finally flash-bangs me - he's about to knife me from the side when I ran backwards - he sailed past.
He tries to knife me, fails, so runs off, trying to get a shot at me. I was about to charge after him, when I gave up. M93 out, 3 rounds in his arse, game wining kill.
His response? "Oh I didn't know you could have a gun with a riot shield..."
BC2 - I drove a tank of what was effectivly a cliff, trying to avoid A/T gunners. And landed on an enemy blackhawk.