There are sooo many wonderful places and beaches here in Thailand, and I don't know which one to recommend to you. But I do know one thing for sure, and that is that you will be in Thailand during the Thai New Year Festival around 13-17 April, and being here during that period you simply must not miss this festival of joy and happiness... and not to talk about the big water splashing fun and partying, so try to spend a couple of days somewhere where this New Year festival is going on, and have some real fun!!