Holland America ,Princess , Celebrity ,
Royal Caribbean , NCL and Carnival all cruise from Seattle . All do a 7 day cruise round trip to Alaska.
Determine what is important to see and how much time you have (min 7 days).
A good travel agent will help you determine what is best for you. The TA by asking
1 - your age
2 - activity level
3 - there are other questions they may
If you want more than 7 days you might have to go to San Francisco Princess sails a 10 day cruise.
If you want 14 days then you will have to sail from Vancouver BC. A number of ships do a 7 day Northbound and 7 day southbound to Anchorage
(actually Seward or Whittier)
SS Ithaca , Volendam , Mariner of the Seas (x2) , Veendam , Coral Princess , Island Princess (x3) , Emerald Princess,Sapphire Sapphire (x3),Diamond Princess