Fiji, Fiji
If you can't be happy in Fiji then I don't think you'll ever be happy. The place literally screams happiness, the locals walk around smiling, calling 'Bula', Fijian for hello, to everybody in sight. Waves are exchanged by every car driver and pedestrian. It's a good job it's not over populated otherwise their arms would constantly ache from all the action!
At first it's hard to get use to, friendliness is a pretty alien thing where I'm from. You're only friendly...