We will be joining the Mariner on Oct 4th. This will be our second cruise on this beautiful ship. We really enjoyed mornings in the library/computer area. There is a wonderful cappuccino machine (and pastries!) and it is a great gathering place for passengers to socialize.
We also had a suite with a butler. We didn't think we would use his services, but he gave us suggestions for his services and we took him up on it! We asked him to make all of our dinner reservations, and to arrange a dinner in our suite. He also arranged a tour of the engineering area(not the engine room) for my husband. At our request, he arranged a small cocktail party, including sending out the invitations. He was absolutely top notch in every respect!
We also enjoyed the Observation Lounge in the evening. There was usually an pianist or singer. Really lovely.
As Sue pointed out, anywhere on the Mariner is wonderful!