its gotta be pierce/garnet over welker imo.
Pierce was drafted by the celtics and spent his entire career up until this point with the Green. Through thick and thin he stuck around, and eventually brought us another title. he was the cornerstone of the team for so long its going to be hard to see him go out wearing another jersey
Welker on the other hand was brought in, never won a title, and then left for less overall money. Welker was bit of a drama queen on the way out, and when we needed him most he dropped the ball. literally.
Welker is just another guy, where as pierce will go down in boston sports history with the likes of brady, bird, and hopefully some of these younger sox players like pedroia.