Barbados is the island with it all. It has the wonderful white sandy beaches, peaceful scenery, and lively nightlife to go with it. The quality of accomodation is excellent and the locals are very friendly. To the point where it is safe to go out most places without any fear of danger.
Everything is nearby as the island is only small. This is great for seeing whatever you want to and trips like driving around the island can be completed in a single day. Plus it's harder to get lost as you can pretty much always see the sea wherever you are.
I think it's the best place I've ever been and will continue to go back, as do many others.