My first cruise was with Carnival. After cruising with others, there is no way I would go back to Carnival. The others were cleaner, better food and better service. I did NCL to Alaska and would use them again. My wife did another cruise with NCL with friends and enjoyed the second cruise as well. We have done Disney 3 times and is my fav. I would use them again without the kids. The food and service was top notch. I hate going to Disney World but loved the cruise line. Their island was unbelievable.
My first was a Norwegian, and I loved it. Afterwards, I went on a Carnival and hated it. After this, I went on a Norwegian and hated them - they've gone really down hill over the past few years, gotten dirtier and the staff was very rude. Plus the food was horrible. However, my next Carnival was awesome - they've improved a lot.
However, recently I was on a Costa Cruise (in Europe) and I have to say that it was one of the best ships I've ever been on.
Every cruise I ever took was fun. Never had a bad experience yet. I've been on Princess, Carnival, Norwegian and Royal Caribbean and I would cruise with any of them again,but I have to say that Royal Caribbean has the upper hand in my book. Looking forward to my next one on the Allure next spring.