Alaskan cruise - NSFW

[young nut]

So for a combination gift of Christmas and my folks 30th wedding anniversary, I've decided to send my folks on an Alaskan cruise. They have never been on a cruise before, but they have said many times that they would love to. They have also said that they want to see Canada and Alaska, so i figured a cruise would be great for them. They live close to Seattle, so their port of call would be Seattle.

Have any of you been on an Alaskan cruise? How did you like it? Any suggestions for a certain cruiseline? The good/bads of the trip? Also, what types of clothing/accessories should they bring?

Thanks OOT, oh and a hot chick -