Vancouver-Jasper-Banff-Lake Louise-Calgary

I would probably take the Coquihalla across to the Okanagan and spend the first night there. It'll be busy in July but still a nice place to see (unless you go there often). Then head up to Jasper on the yellowhead. I'd spend a couple of nights there if possible. Take the Icefields Parkway to Banff, there are lots of things to see in the Lake Louise/Banff/Canmore area, before heading to Calgary, it would be nice to spend a night in that area too.

We've been back and forth a few times, various routes. It's very nice trip!