Peyto Lake: The Best Lake View in the Canadian Rockies
The main platform is crowded. The better view is only about five minutes away.

Why Peyto won
There are prettier lakes to sit beside and better lakes for canoeing, but for the first wow factor, Peyto stole the show. The turquoise color was almost ridiculous, and the huge mountain valley around it made this one of the best views of the trip.
If you are driving the Icefields Parkway, this is the stop I would consider non-negotiable.
The main overlook is not the best experience

The main viewing platform is where almost everyone stops, and it can be extremely crowded. The photo above is exactly what it looked like when we were there.
Our tip: go left
Once you reach the main viewpoint, do not immediately turn around. Follow the trails to the left and explore for about five minutes. There are several small offshoots, so do not overthink the exact route.
We found a rocky viewpoint with virtually nobody there, and we actually preferred the angle. We explored some of the paths to the right as well, but the left side had the better views.
Our Verdict
Best lake view in the Canadian Rockies. If you stop at only one lake viewpoint on the Icefields Parkway, make it Peyto.