I got two unofficial ones...
In Pokemon, I have my trainer card's battle cry set to "AHHH, ACID!!!"
Also, I was playing TF2(right after the Australian Christmas update). I had unboxed the Fists Of Steel. I was playing on Badwater, when I spot a Brass Beast Heavy in the corner completely raping my team. I then proceed to whip out the Fists Of Steel and charge the Heavy, eventually beating him to death with a few health points left. I did this all while screaming into my mic, "SILLY *****, YOUR SIMPLE WEAPONS CANNOT HARM ME. I'M THE JUGGERNAUT *****."
It ranks alongside my Invisible Spy Hunstman Headshot and my Uber-Charged Invulnerable Air-Blasted Reflected FLaming Critical Arrow Headshot as one of my proudest moments of utter epicness while playing TF2.