Rainier is amazing. I love hiking in the North Cascades. My favorite though, is the whole Olympic Peninsula. I love the rainforest. I love watching a heard of Elk move through the moss covered trees and ferns. I love the beaches. Cape Flattery is fun to see. It would be fun to stay at the Lake Quinault Lodge. You can take a ferry from Port Angeles to Victoria for a day which is a really great city. You can visit Vampires in Forks which is totally disappointing but your wife would probably love it. Hiking on Mt Olympus or anywhere else in the area is awesome (I'm partial to the Hoh river trail). The whole place is just spectacular and very unique in the lower 48.