I've been in a couple...but my favorite and coup de grace (if that's how you spell it):
Kid I knew in middle school, he was a punk ass but somehow we got along on random days. Well there was a girl who I ended up having this huge crush over (I mean, seriously...she was freakin' beautiful)...well guess what happens, I go to make my move and this little douche pretty much steals her away. And he pretty much rubs it in my face. So we had a little scuffle in the halls about it and he challenges me, my house, after school. Ok, whatever. He comes to my house (by the way, with ANOTHER girl) and we get into it. It was pretty brutal, no blood or anything but I remember being sore in the morning. Well he gets the upper hand on me and the next thing I know, BOOM! I pull out a front gullotine out of nowhere, to the point where he looked out of it. So I let go and he goes off running, along with the girl.
That was pretty much it. We didn't really say anything to each other again. Sad thing was that I didn't get the girl, but I have a moral victory under my hands. I'm typing this and i'm pretty damn sure the little punk's somewhere in prison or juvy.