Interesting thread. I'm planning a trip out west this summer and will be curious what other suggest.

Of the places I've been in North America, Banff/Jasper is amazing but can be swarming with people. I think my favorite area I've been recently are the Glacier/Yoho/Kootenay National Parks in Canada. The provincial parks in the area are nearly just as beautiful and no where near as busy. You need to be OK with bears though.

International:
Dolomites are amazing and you can't beat the food. Northern Pakistan/India/Tibet are beautiful but can be a little tricky to visit. I never made it to Nepal but heard it was awesome. My international bucket list includes Kyrgyzstan, Tasmania, and Hakkaido.