Not to turn this thread into something else, but...
'96 Bulls or '86 Celtics?
I'm going Bulls, here. I might be a tad biased given my geographic affiliation and fandom of the team, but - really. No other team has accomplished 70 wins, let alone 72. Their point differential is absurd, and are one of, if not the only, team to rank first in most offensive and defensive categories.
You have (almost in-arguably) the GOAT in Jordan, who may not have had the hops he did in the 80s and early 90s, but could still score on you at will with a better mid-range, long-range, and post game. He also may have won DPOY approx. 10 years earlier, but I think he was even better at this point. You have Pippen, who could also efficiently score and was arguably even better on defense than Jordan (and even with a DPOY, Jordan is frankly underrated on the defensive end - that tells you something). You have Rodman, who was basically Moses Malone without the scoring prowess, and a great defender in his own right. Ron Harper, who couldn't score at will like he did before his injury, but (seeing a pattern, here?) turned himself into a terrific defensive player...and you had Toni Kukoc, who could have been a starter on 85-90% of the teams in the league...mostly coming off the bench.
I get the '86 Celtics worship with their HOF cast, but let's be honest, here; Bird (and Magic, for that matter) were never top tier defenders. That's not to say there weren't weak links in the Bulls (i.e. Longley), but I feel that the greatest player ever, and another guy who is top 5 at his position, still in their primes, with the entire team from 1-5 playing excellent defense, is extremely hard to argue against.
Very interesting comp.
On paper, it's very close. The Celts were a combined 50-1 at home that year, regular season and playoffs. It was near impossible to beat them at the Garden. By '96 the league was a little diluted, what with the influx of expansion teams. The '86 East was also STACKED, much like the West today.
Forget about all of the other teams -- the '86 Celts had the GREATEST inside scoring of all time. McHale, Larry Legend and Parish. Parish had the muscle, McHale had the crafty post moves that would rival Hakeem, and Bird could score from anywhere on the court. Walton found a niche off the bench, and could score in the paint too.
While Bird was never an imposing man defender, as a team defender he was top-notch, and Defensive Win Shares rates him as one of the better defenders in the league in his prime. He was awesome at intercepting passing lanes and had great awareness.
They had DJ at the point, who was the Conley/Ron Harper of that epoch, an excellent two-way player that was a really good defender. McHale was an all-NBA defender. Walton could protect the rim with the best of them.
Teams didn't really shoot 3's in that era, but they had Larry shooting near 40%, and Sichting, Wedman + Ainge would have had a field day with that shortened 3 pt line, particularly Bird who shot so many long 2's with his foot on the line.
SO.....they were devastating both inside, out, and at the mid-range, dominated defensively, couldn't be stopped at home with their raucous fan base. Number 2 in FG%, number 1 in FT% and 3PT%, number 1 in rebounding, number 2 in assists, number 1 in Offensive Rating, number 2 in DRating.....where was their weak spot?
Now, the case for why the Bulls were the better team is just as strong. GOAT perimeter defense, toughness + mental fortitude. They had the best scorer of all time and arguably the best rebounder. Kerr was a magnificent floor-spacer, and could catch-and-shoot with the best of them. Kukoc provided a spark off the bench. Pippen was Lebron Lite. As an all-around player he will never get his due respect, playing in MJ's shadow, but other than lacking range he was really excellent in all facets of the game. Great offensive rebounder, great Point Forward skills, deadly in transition, could guard 1-5 (they say 1-4, but they put him on Divac, Mutumbo at times).
Longley was an afterthought in their system, but he was a serviceable big man, and a big body on D.
Both teams have match-up advantages they can exploit: Rodman can't guard the triumvirate of Bird, McHale and Parish all by himself, and both Parish and McHale had unbelievably long limbs. They could get a shot up over anyone.
The Bulls had MJ, whom no one could guard. Too big for DJ and Ainge, too quick for Bird and McHale. Even at 23 he lit up the '86 Celts for 63.
Toss-up. One is 1a and the other 1b for me, depending on how I feel that day.