Taking a ferry north from Canada has got to be one of the best ways to go to Alaska. From Prince Rupert, my journey took me through the Inside Passage, along the Gulf of Alaska and into Prince William Sound. Same route as most cruise ships, but at a fraction of the cost. It wasn't fancy, but the scenery was still spectacular. Especially as we got into Prince William Sound and the snow capped mountains started closing in on us. The air was so crisp and cold you could almost taste the ice. It was just incredible.
For the first part of the journey up to Juneau I chose to rough it and sleep on the floor of the aft viewing gallery. Not the best without a sleeping bag, but manageable. They actually had a solarium you could sleep in as well, which was their fancy name for an indoor deck with a sunroof and plastic deck chairs. Drafty and fairly uncomfortable without a sleeping pad, at least the viewing gallery had carpeting.
On the second part of the journey from Juneau to Whittier I booked a roomette. And I was so glad I did. It was nothing more than a closet with 2 shelves to sleep on, but at least I had a place to put my stuff and have some privacy. This leg was much longer (40 hours!) and turned out to be more crowded then the earlier one. All the good sleeping spots were taken, every deck chair was full and there were a few tents set up for good measure. It was like a big slumber party.