I've been on Norwegian, Carnival, Norwegian, MSC, and Costa in that order (only counting week longs, not weekend cruises). I would rate the first Norwegian as the best, but the third one was terrible. By the ship itself, probably MSC, but Costa had the best service (if you remove the smoking and billion kids in adult areas that constantly annoyed us).
If you have been on a cruise, which cruise line do you like best?
Please comment on the ship you were on and where you went.
We have just started taking cruises. Been on a few now. All our friends are huge cruise buffs. Every one of them insists Royal is the way to go. Seabourn is great, but very "high end" (as is Crystal). Disney is pretty good, but very pricy and still best if you are traveling as a family with kids.