This video is from a college game, but it is still amazing. During a free throw, the ball bounces of the back of the rim and appears to get stuck on the front of the rim. It just sits there for a good second before finally deciding to fall in. Crazy.
(It's probably a good thing the ball decided to finally accept it's fate and fall to the earth. I've heard Isaac Newton gets PISSED when someone starts messing with his laws.)