Remember when Steve Francis had the dunk in the 2000 contest that slipped out of his hand and he slammed it down with his wrist? Ben McLemore's dunk in the freestyle round was basically the same thing, except left-handed.
This one didn't do much for the crowd live, but it benefits from replay, as do many great dunks.
The off arm is a great touch, and Ben reached wayyy back to get that one. Thus, I give this one: