What is the best cruise line?

I want to take a cruise, caribbean I think. But what is the best cruise line and ... is it better to use one of the online sites to book (expedia, cruise only, ect ) or go to a travel agent here in town that books cruises (like spears travels)?What is the best cruise line?
I have been on all lines. It depends on your age. Carnival is more younger crowd and Holland America is Senior citizen crowd. Those are the best ones I have been on. I would suggest Carnival. No need to book through an agent but sometimes they do have great deals you don't see online. I got a two for one special from one once.What is the best cruise line?
I've been on several and prefer Carnival the most. The staff there are very helpful if you have any problems. Food and entertainment are exceptional! My bf and I going on an Eastern Carribean 7 day cruise next month. This will be our 4th time on Carnival and would recommend it highly for young to mid-aged couples and/or families. You can't go wrong with the low prices either. You should probably go through a recommended travel agent to book it. If you go online to book, make sure you get the optional travel insurance in case you run into any weather delays or cancellations of flights if you are including air fare.