I wish I were as lucky as you. I was scoping the Celebrity Solstice before its inaugural and would love sailing on a new ship.
I'm glad I'm not alone in my partiality to Princess. We saw the Ruby docked in Rome and it was humungous. I can't even imagine the size of the Oasis. In any case, I think I need lots more cruises under my belt before I can really say what my favorite cruise line is.
As far as my favorite port, this is soooo difficult but I would have to say Venice was it for me. It was so over the top, the romance of the seas, perhaps, winding thru the canals. This is the place to fall in love with life! How mushy was that, haha. Everyone should sail down the Grand Canal at night just once in their lifetime, (sigh!)
The other ports were just as wonderful to explore. I absolutely loved Capri, Rome and Barcelona. The Achillion Palace in Corfu was unbelievable -- google it and enjoy its beauty!
Okay. Back to reality -- haven't boooked another trip yet. May stay domestic and try planning a New England or Alaska adventure down the road.
I wish you all the best in December and will definitely want to hear all about the Solstice!