The 2008 Celtics team was a very good team.
They got pushed to 7 by the Hawks and Cavs mainly because Joe Johnson was having an outrageous series, and of course the Cavs had Lebron and anything can happen with him.
People try to dismiss them a bit because of those two series, but I still think that is one of the best individual teams of all time. Extremely well rounded, strong defense, and a go-to CLUTCH scorer in Paul Pierce.
That team probably repeats if KG didn't get hurt the next year, and could have won again the following year if Perkins didn't get hurt against the Lakers.
They had a legit shot at a 3-peat, but it got derailed by injuries.