Unless your international flights are limited to Mexico and the Caribbean I think Southwest would be at the bottom of the list given their limited international flying, upgrades and lounge access.

Jetblue and Alaska/Virgin are next but for different reasons. Alaska/Virgin gives you the international and lounge access but their network out of New York is limited compared to Jetblue. Unless Jetblue has something bigger in mind their international network is only slightly less limited than Southwest.

United/American/Delta then are much of muchness depending on whether you loathe EWR or love it. If you don't mind doing most of your flying out of EWR then United gets you most of the above although I would also put it behind AA and DL in terms of punctuality into New York.

The difference really between DL and AA is where you're going to do your international flying. AsiaPac or TransAtlantic. AsiaPac it would be AA hands down through their partners whilst DL has the advantage TransAtlantic. Everything else they are pretty similar.