Not that I've been to many places in the Carribean, but one you may not know of is San Andres, Colombia.
It's an island closer to Costa Rica than it is to mainland Colombia, but it has a very rasta/carribean style.
You have some HOT Colombian women, tons of activities to choose from (like taking a submarine to shark reefs, snorkeling to see an underwater aquarium, ATVs, etc...) and the land is barely touched by tourists, so it's not commercialized yet and everything is dirt cheap.
You can also checkout Captain Morgan's cave, house and even party on his ship at night in the middle of the ocean!
Drink some "aguadiente" if you're ever there.....
Aside from that, as people said you'd find it hard to not enjoy Costa Rica
