There are two things I generally don't debate:
1) Religion (with anyone)
2) Baseball (with New Yorkers)
Thanks to Summer Fridays (our company lets us out of the office at 2 p.m. on Fridays between Memorial Day and Labor Day), I caught the below featured camera phone photo ops on an uptown no. 1 train during a heated debate regarding the Yankees and the Mets, which diverted momentarily with a few mutual stabs at the Red Sox, a quick dispute over homerun records, and then came full circle back to the Yankees.