Peter...Sailing out of NYC we have Carnival and NCL year round and Princess sailing in the Spring/Summer from Red Hook in Brooklyn. Holland America also sails out of NYC on a less than frequent basis. Just across the river, Royal Caribbean and Celebrity sail out of Port Liberty (Bayonne) on a year round basis. Boston only offers NCL Spring through Fall!
We have the best choices for cruise destinations out of NYC. The Carnival Splendor has a sliding dome over the Lido pool making the Lido (Beach) deck, useable in any weather.... a big plus for Winter cruising out of NYC!
Hope this helps!!!