Best first move/strike in a fight?

flying knee

MrZipplokk...I saw a street fight behind my karate studio when I was a kid.  The guy kicked his opponent very hard in the groin.  When he bent over in pain, he kicked him in the face, hard.  The guy went down, got up and was staggering, looked like he got a possilble concussion.  I can still remember the sickening thud of that kick to the face, ouch! 

Gary Hughes