What to see in Boston and NYC

I have a two week ‘holiday’ coming up soon with a week each in Boston and NYC. Apart from Intrepid, what is there in these cities to see and visit? I already have a grudging agreement to the Intrepid visit from the wife-to-be, but it would be handy to have one or two ‘surprise finds’ with which to break up the shopping and Sex and the City tours!