I browsed some peeps' answers, and the general consensus is that it's an all-inclusive, 5 star resort and I lost all my luggage except these five items that I luckily had on me, so here goes!
Sunblock (the goooood shit: Hawaiian Tropic Sport 30SPF Oil Free Waterproof Aerosol kind), iPhone & all its essential accessories (they get 3G reception in Paradise, right?), my most flattering bikini, super sweet shades and an amazing book.*
If for whatever reason this isn't an all inclusive resort, then definitely enough booze to last the entire week. :) But in all seriousness, it's not paradise if it's not luxurious! And I always travel in style.