Alaska bound

So, planning a trip to Alaska and back this summer.  We will be heading up through Great Falls, Montana taking the eastern route and then plan on coming back some other way.  Haven't figured out that yet. We are planning to spend two months just touring Canada and Alaska.  This is our first trip driving to Alaska but have flown up twice before.  For those of you that have done this before, any "must sees" that you recommend along the way.  Thanks everyone.