Hypothetical

[Soul_Patch]

Suppose that back in 1976 the Buffalo Braves and the Cleveland Cavaliers faced on in the first round of the NBA playoffs, and further suppose the series was best of seven. Now imagine that each game took five overtimes to determine a winner, and the series lasted the full seven games. However, the winner of the Cavs-Braves marathon then went on to get swept in the next round, and the winner of that series was swept in the next round.

Would that first round series between the Braves and Cavs be considered the best ever?

If so, then maybe this series between the Bulls and Celts is pretty good. If you think the hypothetical 1976 series between the Braves and Cavs was merely an entertaining first round match-up otherwise lacking much historical importance, well, then, you have your answer as to where the current Bulls-Celts series stands in history.

[fairweatherfan]

I've always figured there's a difference between "greatest series ever" and "best series ever".  Greatest has to do with who's playing and in what situation - it should be the conference finals at least, or an earlier matchup where it's agreed that the winner will almost certainly take the title, and they go on to do so (like Spurs/Suns a couple years ago).  Rivalries count, career arcs count, even performance in later seasons counts (the 87 ECF wouldn't've been quite as epic in hindsight if that Pistons team had fallen apart afterward). 

Best series ever, on the other hand, should be independent of context and solely focused on what happens within the series itself.  Doesn't matter who's playing, in what round, or what they go on to do, it's purely competitiveness, drama, and level of play within the series itself. 

By these criteria (just my own thoughts) this isn't one of the greatest series ever but is certainly one of the best.  Same with your hypothetical.  Just my 2 cents...

[Txusberg]

But what if we win today and this epic series is only the first step in our long way in the play-offs?. If we win today, the 2nd round against Orlando won't be as tough as Chicago and i can totally picture us in the ECF against the Cavs. But we have to win today first to make some History. Go Celtics!

[Redz]

Historical context is tough to determine until some time passes.

If the Celts and Bulls end up playing each other in the playoffs for years to come and it turns into a great rivalry, that would help.  If one of these two ends up winning it all it would help.

It's hard to say.  One of the best baseball games I ever saw was a high school game between two teams that weren't even all that great.  They just matched up well, and played a very suspenseful, intense game.