Loved the Sunshine - it has lots of fun things to do, like a pretty intense ropes course (try doing that while on a moving ship :). There is mini golf, great movies on the big screen on the Lido deck every night with free popcorn, and TONS of deck chairs and even couches and hammocks and cool clamshell loungers in the adult Serenity are which is HUGE - 3 decks! They also had several great comedy acts - like a new comedian every night, and other great entertainment every day too. I am not big on Broadway style shows at all, been there and done that, so I was really happy that they instead have a creative bunch of shows in a more intimate setting.
You won't find better food and more variety of food options than you will with Carnival. that is just a fact - whether you are a foodie or just enjoy comfort food. We have tried Royal Caribbean, and Carnival's food is honestly better - consistently too across 9 different cruises I have taken with them over the past 14 years. Norwegian did not have the quality or variety of Carnival either when we cruised with them to Hawaii.
Then there is the staff Carnival employs. If you have ever sailed with Carnival you will know what I mean.They are international and that makes a huge difference. You have the chance to interact daily with staff members from all over the world, Romania, Bulgaria, France, Australia, Singapore, and on and on. And they consistently are upbeat, positive, and seem to genuinely enjoy helping you and will do whatever they can to make your stay pleasant. This has happened without fail on all 9 of our cruises with Carnival. The fun we have interacting with the employees is one of the reasons we stick with Carnival. On the other cruise lines we have sailed with you feel like you are in a cafeteria, with a corresponding generic type of service from the staff. There just isn't anything special about it.
Love the ship. Love Carnival.