According to Tripadvisor.com these are the best beaches for 2011.
I must say I agree.
Providenciales, Turks and Caicos
Boracay, Filipini
Aruba, Caribbean Islands
Punta cana, Dominican Republic
Tulum, Mexico
Myrtle Beach, USA
Seven Mile, Cayman Islands
Matira beach, Bora Bora
Isla Mujeres, Mexico