The Alaska Marine Highway (state ferry) and the Alask Highway are both outstanding. The ferry has wonderful double-bunk rooms with full shower bath en suite, great food in the dining room, and very comfortable observation lounges. Cafeteria-style eating was also very good. Pricing is moderate. Scenery is awesome!
The highway from Skagway to the Yukon and points east and south was also wonderful. It is "chip-sealed" but mostly is as smooth and comfortable as any fully modern two-lane in the lower states. Good facilities available at frequent intervals, and very nice accommodations available as well.
All this, and Alaska (!) too.