Steve at Clips Nation has the full list of links to the SBNation teams rivalry day posts. It is fascinating to see which teams other teams' fans consider their rivals. When your team is terrible, they don't have many options for rivalries. When your team is trying to break into contender status, then they focus their ire on the team standing in their way. And when you are at (or near) the top for a long period of time, you can take your pick of contentious contenders.
That's where the Lakers and Celtics are. Here are a few that consider the Celtics their rivals.
At Posting and Toasting, the Knicks fans have voted the Celtics to be their top rival. (That's cute)
Who is the Knicks' biggest rival? - Posting and Toasting
Reasons: A bunch of recent games that came down to the last second, a recent history of small fights and hard fouls, the 2011 playoffs, Paul Pierce, Kevin Garnett, Rajon Rondo, and oh man I hate the Celtics so much.
Over on Hot Hot Hoops, the Heat fans have also voted the Celtics as their chief rival, despite other decent options from the team's short history including the Bulls and Knicks.
NBA Rivalry Day: Which team is the Miami Heat's biggest foe? - Hot Hot Hoops
This rivalry is "newer" but has become the biggest enemy of the Big 3 era and has the potential for even more epic battles to come, or at least until Kevin Garnett and Paul Pierce hang it up. The Big 3's first regular season game was against the Celtics, whose triple superstar formula is acknowledged to have inspired the Heat's own championship blueprint, and the battles in both postseasons that have seen the Heat victorious but not without giving their all against a team that always plays their best against the Heat. Swiping Ray Allen aways from the Celtics months after beating them in 7 games in the Eastern Conference Finals just adds more fuel to the fire and another fascinating storyline to a rivalry that is getting more and more interesting.
There may be more that I'm missing. Some haven't been posted yet and there are several teams fan-bases that would likely consider us a primary target for their "hate" (the Bulls and Hawks come to mind).
But of course, at the end of the day, there's really only one team that matters.
NBA Rivals -- With Plenty Of Rivals To Choose From, Only The Celtics Make The Grade - Silver Screen and Roll
No Laker fan needs to be told this to remember it. There is another team as successful as the Lakers, more successful in fact, in the only metric that truly matters. They are the Boston Celtics, and even though some will write off Boston's dominance as a remnant of their distant past, there is no doubt they are the Lakers' chief rival, because nobody else is even in the competition. Boston has 17 titles. The Lakers have 16. After that comes Chicago with six (all from a once in a lifetime player who isn't coming back). It can honestly be said that no team is likely ever to surpass either LA or Boston in total championships, and so the two teams remain destined to fight each other into the sunset for the title of league's most victorious franchise.
...aaaand queue up the "Minneapolis Championships don't count" argument if you like. I don't think you'll convince any Laker fans.