Originally Posted by number_6
US: ATL, JFK, EWR, ORD, SFO, DCA.
I assume the OP is interested in US airports and not ones that are limited to the airport, otherwise this is like asking... oh, what analogy to use... which birds fly?
BWI, MDW, PHL....
JFK is more of a rail shuttle to another train station (thanks, feds). Same for EWR.