New to cruises - need help choosing!?

I just came back from a cruise. It was a 7 day western caribbean cruise with Carnival. I like carnival because they are cheap and fun. The only downside is there tends to be quite a few kids around. This doesn't bother me much coz they tend to be in the pool most of the time which I don't do when on a cruise. A more adult oriented cruise line is Royal Caribean cruise line but I think they tend to be more expensive. I would suggest Carnival. Go on their website and they have a list of all their cruise destinations.