Ideas on Alaskan Cruise?

[AzNMpower32]

I'm trying to help plan an Alaskan Cruise for my grandparents and relatives, and I don't really know where to start. I've never planned cruises, but I'm sure some of y'all have some experiences so perhaps you could help. (By the way, I'm not going to be actually attending the cruise)

They're looking to do a 7-day cruise that leaves from Vancouver sometime in May. They're all of the older set (6 people, ages from 47-70)and want a good quality cruise. Any reputable cruise lines that I could search up? I did a forum search and found positive comments on Holland America and Norwegian Cruise lines. Am I missing any?

Holland America has tons of routes and different ships. Have any of you had personal experience with any one of these?

Any thoughts or comments greatly appreciated.