British Virgin Islands

Devil's Bay - Virgin Gorda - British Virgin Island

Maldives

FFS - it's Devil's Bay in Virgin Gorda. Just Google it and look at the images. There's even a link in one of the comments.

Sardinya

koh samui

Devil's Bay, Virgin Gorda, British Virgin Islands (BVI). You can see the exact same picture here, in a list featuring the best beaches in the world:
external link

Seychelles

It's Devil Bay on the island of Virgin Gorda in the Caribbean.

Australa

Lavezzi

La Digue island, Seychelles

Palombaggia, corsica