Definitely Princess. No question about it.
Princess have much more of a "relax, enjoy" product, while RCCL are a more "take part in activities" cruise.
St Thomas is THE place to buy a little bit of jewellery to remember your honeymoon by. Also, you simply must take the champagne catamaran trip to St John. Just wear plenty of sun block- we didn't!
Princess Cays is the place for a romantic stroll along the beach, hand in hand......
The extra sea days are perfect for romantic relaxation.
They are the line that lives up to the "Love Boat" description, and if you are just married, they will give you all sorts of extras, like champagne and chocolate dipped strawberries in your cabin, a cabin upgrade, card from the Captain, all the things that RC don't do.
Princess also have a newly launched "department of romance"... no other cruise line has one to my knowledge. They can organise proposals on the giant movie screen, you name it, they can do it.
Princess' "anytime dining" means you can eat exactly when you want, and if you fancy a table for 2, they can do it. Usually it means a 15 minute wait, but they give you a pager so there is time to go to the bar for an aperatif, then return for "dinner a deux".
We renewed our vows on Golden Princess a few years ago and the experience was out of this world. We had a champagne breakfast on the balcony (free), a 1/2 hour spa appointment (free), a champagne reception (free), a framed souvenir photo (free) and the Captain invited us to the Bridge the following day.
Over the week we had 4 bottles of champagne, all free. One because we were renewing our vows, one because it was my wife's birthday (we married on her 21st), one because it was our wedding anniversary, and one, i think, because they lost count!
We were visited by the "Cabin Upgrade Fairy", and had canapes delivered to the cabin every evening, and chocolate dipped strawberries every morning.
That was our first cruise, we have now done 15 with Princess and they are always good, but not quite as good as that one!