I have never been to Alaska, but I have cruised several times to the Caribbean and my choice is Royal Caribbean cruise lines. However, the really large ships in the Royal Caribbean fleet would not be my choice - way too many people. The cruises I took were always the smaller ships. Although not geared to adults, the Disney Ships are wonderful! The private pool area for adults is enforced and was very nice. My husband and I went with our teenage son and we totally enjoyed it. You can PM me if you want more info. Wish I could come along - I love to cruise.