A good one is a sarcastically spoken term used to describe someone that is being/or is a big douche bag, an idiot, a cheater, a liar, a dumbass, or someone that is an outright fuck tard.
"Did you see that guy over there that thinks he's cool , but he only has 2 teeth? "That guy is a freaking good one! I would never date a good one such as that !
by ThebestJV February 26, 2016
I'll knock you a good one
by Wheesy May 18, 2016