1990's: Bruce Bowen
Bruce Bowen had a wild ride getting into the NBA. If you follow Basketball in the early 2000s, then you know Bowen as a three-time champion, five-time NBA All-Defeive first team, and three-time NBA All-defensive second team.
Before that, Bowen went undrafted in 1993. Between 1993 and 1997, Bowen played for five teams, starting his professional career for the French team in 1993–94. In 1997, the Miami Heat offered Bowen a ten-day contract. Bowen played for the Boston Celtics for two seasons and the Philadelphia 76ers for one year.
Bowen returned to Miami for one year and was on the All-defensive second team. Then went on to have a promising career for the San Antonio Spurs. What would have happened if Bowen stayed in Miami? Bowen is one of the first "Three-and-D" ( shot 39% from three) players to enter the league. Bowen next to Dwyane Wade on defense would be fun, and Bowen hiding in the corner on offense would have provided floor spacing for Wade.
My mind also goes to when Miami Acquired Shaquille O'Neal. Adding Bowen to that era makes Miami deeper and adds a wing who knows his role. With Bowen already, does Miami still look to trade for Antoine Walker and James Posey? Bowen's staying in Miami isn't talked about enough. He could have helped some of those Shaq/Wade teams.