Best cruise line for honeymoon and website to book?

I'm going on a cruise for my Honeymoon. I'm using Carnival, and we're going to the Cayman Islands, Jamaica, and Cozumel.
I've been on Carnival before, and I love it.

My parents have used royal carribean several times and say they’re amazing! I haven’t heard the greatest things about carnival or princess.

Which cruise line you choose is going to depend on what you're interested in.
Carnival is cheaper, to me not as nice. It's more of a party cruise line.
I love Royal Caribbean. They're a little more expensive, but I feel like they have a little nice ships with better customer service. Plus they have fun stuff (depending on the ship) like rock walls, mini golf, and the surfing simulator!
PP mentioned Princess, that is for the older crowd. Definitely not for partying
I've heard good things about Celebrity but haven't personally cruised with them.
I personally love Disney, but we're a Disney family. They're also expensive, but everything is great. I love the food, broadway style shows, character meet and greets, clean ships, and the newer ships have a water roller coaster.

We are going through Carnival. The company has been a huge help for us.

My H and I love Royal Caribbean and Norwegian Cruise Lines. We have taken cruises on both and are actually leaving Sunday for our honeymoon cruise on Norwegian. One of the things we like best about Norwegian is that they include a drink package when you book a room so you don't have to worry about the cost of drinks at the end of your vacation.

Best cruiseline is totally dependent on your personality and how you like to spend your time. For example, I wouldn't sail Carnival or Norwegian if it was free, and since you're talking about sailing from Europe I add MSC in that category.

We enjoy Celebrity, but we chose Oceania for our honeymoon. Top notch food and service.

Royal Caribbean is my first choice. I've been on two of their cruises and my parents have been on a ton. They cater to couples, families as well, but not as much as some of the others. I went on a Norwegian cruise with FH and it was nice as well, but Royal is still my favorite. Royal owns Celebrity and while I've never been on one, I'm dying to go on one. It's more upscale than Royal and I hear the food is amazing. Carnival was terrible and I will never go on one again. Food was bad, kids running everywhere, cheap and tacky looking.

But, if you're looking for a romantic, personal honeymoon, I wouldn't go on any of the above. I would go smaller and luxury (Oceania like Red Queen mentioned or similar).

View Quoted Comment Thanks! I've been on carnival in my early 20s and while I liked it, it's not the atmosphere we're looking for at almost 40. We were looking into royal Caribbean as an option so now it's a definite contender!

View Quoted Comment This is super helpful, thanks!

FH and I have been on Norwegian only as we have only done one cruise as part of a family vacation with his family. Personally I loved it. In fact we will be cruising with them again for our honeymoon. The only thing I would change is I wish the hot tubs were hotter but understand they may have regulations that keep them from being too hot. FSIL has been on many cruises and loves carnival.