Between 2006 and 2008 my late wife and I enjoyed three cruises. We loved cruising so much I'm only sorry we didn't discover the delights years earlier. Our first cruise was to Alaska on Celebrity. We loved the cruise, we weren't that crazy about the cruise line. Our next cruise was out of NY and up in to Canada's Maritime provinces. It was an okay cruise but the ship was infested with grumpy and impolite passengers, not the cruise lines fault but YIIIICK! I forget the cruise line, but it was okay. Our third and final cruise left Valparaiso Chile went down the coast through the Straits of Magellan, visited Cape Horn and the Falkland Islands and ended in Buenos Aires, Argentina. It was a two week cruise which we found to be a little excessive in length, but we both loved Norwegian Cruise Lines. When I take another cruise it'll be on Norwegian.
BTW, if you get a chance while your in Alaska, have some fresh-from-the-boat king crab, you won't be sorry!
Steve