The Celtics are not the best team, the Pistons are. The Celtics have yet to prove anything as a unit how could you say they are the best team. Best trio in years? Yeah. But I think you're getting ahead of yourself if you think they are better than the Pistons or Bulls. Also, in the West, I'd take off Golden State and Portland. The Lakers are better than both, and the 8th will be a darkhorse of: Warriors, Kings, Bucks, Clippers, IMO. Other than that I agree with your list.
Right now next season looks very interestin'. Rockets made some great moves but right now about 25+ teams has big chances for the PO, maybe Championship.
1. Spurs 2. Suns 3. Mavericks These are the big 3, like it or not... until some team knocks them off their perch. 4. Rockets - first 2 months will tell us whether we can now call it a big 4. 5. Utah Jazz 6. Detroit Pistons 7. Chicago Bulls 8. Denver Nuggets 9. Washington Wizards 10. New Orleans Hornets 11. Cleveland Cavaliers 12. New Jersey Nets 13. Golden State Warriors 14. LA Lakers 15. Miami Heat ... off the top of my head.
I really think Rockets have big chances for even Championship. We are great team and I really belive we can win series with Spurs/Mavs/Suns. We need healthl, good bench and of course good coach.