If you are strictly talking about the greatest dunk competition ever, than you certainly have to identify one of the epic battles between Michael Jordan and Dominique Wilkins in the 80’s. There just simply wasn’t ever a heavyweight dunk battle of that proportion in the NBA before or after the fact.
But if you are trying to identify the greatest dunk contest performance by a player, you may first consider the year little Spud Webb won at only 5’7″ tall. But in doing so, you’d have overlooked certainly the greatest individual dunk performance in the contest history. Vince Carter in 2000 was on another planet. Sure people love to hate on Vince Carter. But you can’t deny his leaping ability or the ferocity of his dunks in that 2000 dunk contest.