Everyone remembers Dee Brown's iconic win in the 1991 NBA Slam Dunk Contest and then Gerald Green's victory in 2006, but another Celtic put on a show in 1996. Greg Minor, the 2nd year Celtics guard out of Louisville, took part in that 1996 contest.
By the mid 90's the NBA was already tinkering with the slam dunk contest. They had changed the rules to having a timer and players had to complete several dunks in 90 seconds. These new rules made missed dunks a much worse thing and also didn't allow players to rest between dunks. Keeping that in mind, I actually think Minor's dunks were quite impressive in that contest.