see photo link for lakes. my favs are Twin, Emerald, Moraine,

If you only do selective hiking, you should have enough time. We did something similar few years ago. Driving from Vancouver - round trip - total 9 days including stopping at BC Rockies (versus Alberta Rockies), and Okanagan Valley (very scenic, huge lakes and orchards). We spent 3 nights in Banff and 2 nights in Jasper. It should be the other way round.

Peyto is amazing but the viewing platform is also amazingly crowded. If you can get $1.00 per head, you would collect at least $500 to $700 every hour ...
But of course, when you see the pictures, you only see the amazing lake, as if there is not a single soul ... ;-)

I like Twin Lake a lot - very few people bother to go there - extreme scenic, tranquil, and great for kayaking or canoeing.

Lake Emerald is more beautiful than Lake Louise, IMO.

http://www.terragalleria.com/pictures-subjects/lakes/lakes.all.html