You're not road-tripping from Singapore to NYC, are you ? ? ? That could make the 2week target a little difficult. I'd stop in Atlantic City on the way to DC. In NY - if you only have time for one or two truly touristy things, I recommend Ellis Island. There are a number of other threads for food and shopping, so I won't belabor those. In Chicago, if you only have time for one or two truly touristy things... take an architecture tour. The boat tours may be over by now, but there are walking tours. DC is pretty obvious. The smithsonian and the national gallery are both awesome in addition to the Gov't buildings.