In the Loss Of Confidence Episode.
J.J: "Dad your a handsome dude, Mom your a beautiful lady, Thelma Your good looking, Michael your good looking, tell me WHAT HAPPENED TO ME" :lol:!

I know he had some arguably better ones during Season 5, but I think the line above is the funniest the earlier more clownish J.J. delivered! The crowd not only laughed but clapped when he said it.