Check out the Mayakoba development in Mexico - www.mayakoba.com We stayed at the Fairmont and the Banyan Tree - both were very nice, but the Banyan Tree was out of this world and very romantic. We ate at the Rosewood one night, which also looked amazing.
Mayakoba is one hour south of Cancun airport and the hotels will arrange for a car service for you -- all have Escalades and Mercedes for guests. Not once was I ever concerned about any safety issues since all the hotels are in a secluded, gated community. We connected through Atlanta on Delta, but I think there are more nonstop, direct flights from DC to Cancun now.
These resorts are 15-20 minutes north of Playa del Carmen. My husband and I had every intention to go into town one day to do some exploring and eat at some local restaurants ... but the pools and beaches and food were so wonderful at the hotels that we never did it
Are you dead set on a beach vacation? If not, check out the Four Seasons Santa Barbara. UNBELIEVABLE! If I had Oprah's money, I'd live out there too!