[pimlottc]

I'd be interested to know what the "best" stop is based on this - which station has the largest accessible area?

Times Square [0] has the most connections, but Atlantic Av [1] has better coverage of Brooklyn. Hard to tell which is larger, though.

0: https://subwaysheds.com/stop/r16/times-sq-42-st

1: https://subwaysheds.com/stop/r31/atlantic-av-barclays-ctr

[gen220]

If you open it up to include LIRR, NJT and Metro North, Penn Station / Times Square / Grand Central is probably the winner. :)