My trip to NYC in 1999. I'd never travelled alone before - I had the most amazing time. I was lucky enough to be able to stay with friends and family... including my Mum's flatmate from when she was in New York 30 years previously.
Spa day, tea somewhere lovely, cocktails and dinner somewhere smart and a good hotel. Sitting around over lunch and drinks the next day - doesn't matter where, it's the company not the place.
For this couple it would be a two city trip to Boston and New York (maybe a day trip to DC) definitely taking in a baseball game; Red Sox/Yankees. We're not beach people, we're going places and seeing stuff people!
I hate the word but a 'staycation' - you'd be amazed what is on your doorstep that you have missed!
The list is very very long. Washington DC(never made it when I was in New York nearly 15 years ago and I meant to). Also Egypt and the pyramids; Jerusalem; the Burgs of the Middle East... problem is that as I can't deal with the heat and I'm scared of flying it is pretty unlikely!