Recently I took a 14 day journey from Vancouver to Vancouver with my wife. We're in our mid-30's and enjoying cruising life. We gone in 6 cruises now with Princess since our first in 2010. You could say we're hooked. We found the Diamond Princess ship A+ and a toss up for the best. We really liked the Island Princess, but the cozy Club Fusion on the Diamond with it's 40+ big screen televisions and a large dance floor was a big winner. There's no International Cafe or food on Princess ships after 11pm, so that's sort of a downer.
If you go to Alaska, being there 3 times now on Princess, College Fijords and Juneau are my favorite travel locations. College Fijords blows Glacier Bay away in terms of excitement with wildlife and glacier fun. We did whale watching in Juneau with an independent company called Orca Enterprises. I found that the staff really loved what they were doing. It was worth the excursion cost. Juneau has plenty of free stuff to do: hiking, taking the 1 hour city bus to Mendenhall Glacier for 2 bucks is an experience in itself!
I found the game shows on the Diamond Princess to be top notch. I loved the cruise director. He sings and acts in the game shows. (He's great!) Deputy cruise director Dan Appleby is a British guy that gets the crowds riled up with good humor. Diamond's Yes/NO game, Liar's club, marriage game show, and majority rules are not to be missed. Arrive early to get good seats! I enjoyed the trivia every morning on the "Wake Show" that the cruise director and deputy cruise director co-hosted.