Honorable mention
Ray Allen
While Allen may have left a bad taste in many a mouth with the way he left the Celtics, without him, there would have been no Kevin Garnett trade, and quite likely no Banner 17.
Jesus Shuttlesworth was an NBA champion in 2008 of course, and made three All-Star Games in 2008, 2009, and 2011 en route to cementing his legacy as one of the greatest shooters to play the game.
The UConn product averaged 16.7 points, 3.4 rebounds and 2.7 assists per game over five seasons with the Celtics.
Charlie Scott
Scott has the dubious distinction of having been traded away by the Celtics twice, but he had a significant impact while with the team in the middle of the 1970s, winning an NBA championship with the team in 1976 and being elected to the All-Star Game in 1975.
The UNC product averaged 17.5 points, 4.2 boards and 4.4 assists over three seasons with Boston.