M.D.
Yosemite Park
Yellowstone Park
Key West
Washington DC
See a show on Broadway in NYC
ETA: If you have the time: My family drove across the country. We took the northern route west - stopped at Mt Rushmore, Badlands, Yellowstone, and Yosemite. Then we drove down the CA coast San Francisco to San Diego (Disneyland, San Diego Wild Animal Park, San Diego Zoo, Balboa Park, an many many beaches), then back across the south, hitting Carlsbad Caverns, Grand Canyon, St Louis Arch. Both my parents did the cross country sections of driving. My dad flew back from San Francisco while mom (SAHM) took us down the coast (we took a lot of time for that part to visit family in CA), then he met us again in San Diego and drove back with us. So, in all, he took 2 weeks of vacation, and the rest of us took about a month.
It was amazing. I wish I could do something like that, but neither DH or I get that much time off of work.