I would have to say a buzzer beater from halfcourt or beyond. The kind where the buzzer goes off when the shot is in mid air and the ball seems to hang forever. And on the off chance it goes in, it is the most exilarating play.
Being the soccer fan I am, a thunderstrike from 40 yeards out is always good, especially free kicks.
http://youtube.com/watch?v=W5XpXU8TB...eature=related