If you haven't been to Iceland, it should on the top of your travel list. Iceland is one of the most unique places on this planet. I highly suggest you give yourself at least 7 days to complete the ring road, because the weather is incredibly unpredictable and constantly changing. As they say in Iceland, "If you don't like the weather, just wait 5 minutes." Be prepared for all climates, especially if you plan on traveling outside of the summer months.
banff national park:
Canada's first national park, and one of my favorites in North America. Around every corner is a majestic viewpoint with awe inspiring landscapes that'll leave you breathless. Both Banff and Jasper National Park are a must see when visiting Canada. You can see quite a bit in a weekend, as my itinerary only takes 7-8 hours of drive time. Keep in mind you'll be stopping often, especially if you plan to make time for hikes.