We at SB Nation NBA have been doing network-wide themed posts every Wednesday, and this week's is very simple. What other NBA team is the Knicks' biggest rival? We're talking about present day, but I do think that the strongest of current rivalries remain informed by past hostility. That said, here's a case for each of the candidates (a list made with y'all's help):
The Boston Celtics
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.
The Miami Heat
The Brooklyn Nets
Reasons: Geographic proximity, Deron Williams (remember that game last year?), maybe Kris Humphries, a bit of (fugazi) recent playoff history, the rising tide of marketing material insisting that this is a rivalry.
The Chicago Bulls
Reasons: Lingering 1990s playoff hostility, and I guess that double overtime game last season?
The Indiana Pacers
Reasons: Lingering 1990s playoff hostility, Danny Granger runnin' his mouth last season.
The Houston Rockets
Reasons: Lingering 1990s playoff hostility, the whole Jeremy Lin ordeal and the inter-front office weirdness that preceded it.
I'm sure there are more reasons, but I think that's a decent list of teams. Vote!