+2 on Hawaii. Hawaii is always great year round.

Also look at Hilton Head (laid back and great natural setting) or Mrytle Beach (more touristy). Both of them will be hot and humid in July but very comfortable at the beach. The Hilton Head Marriott is right on the beach but a somewhat dated property. The Mrytle Beach Marriott is also right on the beach and newer and nicer. While Mrytle Beach itself can be very touristy, the Marriott property is in it's own isolated section of the beach. If you like Marriott Vacation Clubs both locations have them though they are hard to get on points. For Hilton Head: Barony, Grande Ocean, Monarch, and Surf Watch are on the beach. The other 4 Hilton Head Vacation clubs are not on the beach and are more golf oriented.

--Jon