Where are the good beaches in Costa Rica?

My girlfriend and I are planning on going to Costa Rica for our anniversary. We are both big water babies and from the stories of our cousins who attended a romance tour in the country, Costa Rica has really good beaches. Unfortunately, they really can’t remember the names of the beaches they went to.

I need suggestions from those who’ve been there. What are the good beaches that offer aqua sports? Are there any VIP resorts around? How far will it be from the city? I need help sooner so I can start making arrangements. We don’t have final plans yet but we do want to have at least a solid idea where to go.

If you guys could give me good suggestions, it will really be appreciated. Thank you.