The NBA Slam Dunk contest is defined by its most thrilling competitions over time. Here are some of the most memorable.

The ball found its way to Zack Austin, who gathered and then threw down a ferocious 2-hand dunk that got the students in the Oakland Zoo to jump around.

An alternate definition of a dunk, perhaps one based on which direction the hand that released the ball was moving in, makes more sense. Ultimately, though, whether it was a dunk or not was ...