We like cruising - it's our preferred vacation at this point.
Our favorite line is Disney - we're gold status there which entitles us to some perks that add up to basically nothing. Royal Caribbean is fine, Norwegian is fine. Carnival...is not for us, but a lot of other people seem to like them.
Disney is expensive compared to the others, but the service is better than RCL and an orbit better than Norwegian. (Carnival has service, but 99.8% of the staff on a Carnival ship are employed as bartenders. The other 0.2% drive the ship.) We find there's more to do on the Disney ships and it's obviously geared towards families.
They also have a nice feature called rotational dining. Every night, you eat at the same table, but at a different restaurant. Your maître d', your server and your beverage server rotate with you, so after a night or so, they know you and you know them.
We like heat, sun, sand and blue water, so we tend to look for the seven-day Caribbean cruises. That generally means the Disney Fantasy out of Port Canaveral. Those trips either go to eastern Caribbean (Tortola/St. Thomas/Castaway Cay) or western (Cozumel/Grand Cayman/Falmouth/Castaway Cay.) We took the eastern trip last July and will take the western trip again in August, 2018.
This August, we're cruising out of Vancouver to Alaska on the Disney Wonder. I'm a little apprehensive given the lack of heat, sun and sand, but people rave about the Alaska cruises, so we'll see.
One cruise I'd like to try.....Norwegian has a cruise out of New York City that goes to Bermuda and docks there for three or four days. I've been to Bermuda, but this seems like a perfect way to spend time there.