If you want to stay in the US, it depends on what areas you like. Such as mountains, or seashores, or rivers. Also, it might be fun to rent a motor home, for a week or two, and just travel by yourselves! I did that in Florida, for a week, and had a great time driving anywhere we wanted. Good luck.
I would do the Nice, France then take a train up to Monaco (1 hr or so) . It's GORGEOUS!! OR go to the Maldives. This is supposed to be one of the most beautiful islands on earth (in the middle of the Indian Ocean, south of India) These islands will sink in the next 10-15 years so people should go now when they have the chance.