Rajon Rondo is the best player on this team now (in my humble opinion). He's the leader, the new face of the franchise, and the foundation upon which the future of the team will (in theory) be built upon. With all that said, Kevin Garnett is still the heart and soul of this team.
Everything changed in Boston on that Summer day in 2007 when Kevin Garnett was traded. The Celtics didn't just go from being bad to being good overnight. They went from being NBA players to becoming a team.
Kevin Garnett had all the tools he needed to be a top scorer in the league but he never wanted that. He's been the MVP and he's had personal accolades but I don't think much of that mattered to him. He's all about the team and all about winning. All players say that and all coaches preach that, but there are few NBA superstars who really truly believe it right down to their bones like Kevin Garnett does.
Ubuntu was a clever motivational tactic but it would have been just coachspeak if it wasn't for Kevin Garnett. Paul Pierce did his part by embracing the new stars. Ray Allen sacrificed a lot of his game - at least initially - for the good of the team. But Garnett has been living out ubuntu his whole career. He just finally had the supporting cast he needed where he could make the right basketball decision (like passing out of a double team) and still give his team the best chance to win. In Minnesota, KG taking a shot while double teamed was actually a better option than letting someone else take an open shot - yet he would still pass it out because it was the right play.
Nothing exemplifies this team concept more than his dedication to team defense. Again, he could lead the league in blocked shots or steals if he really wanted to. But he'd rather play sound defense - which is unglamorous and requires working in concert with 4 other guys. A defense is only as good as its weakest link (and boy have we had some weak links on the court at times) but somehow Garnett has been able to keep everyone on the same page. Don't get me wrong, Doc Rivers and his staff deserve oodles of praise as well, but KG is the general on defense. When he yells jump, the foot soldiers don't even have to yell "how high?" because they already know exactly which spot to run to.
A truly elite defensive unit requires communication and trust in each of the other members of the team. It is a bond that develops between them so that they become one interwoven entity. None of that is possible without buy-in from the top down and when one of your best players is your best defender and perhaps the hardest worker, that sets the tone for everyone else.
Rondo has picked up a lot of that from Garnett and I do believe that he'll carry that with him for the rest of his career. But the bottom line is that if Kevin moved on this past summer, it was going to be demolition time to the team. Instead, he stayed and the team carries on. We not me.