I told you recently I'm about to go there soon, so here's the planned route more or less. We're renting a camper van so it'll be basically a roadtrip with some occasional hiking in National Parks (Jasper & Banff) and other interesting places (Whistler & Wells Gray for example). If you're into hiking/nature then West-Canada is where you'll want to go.
We're visiting Vancouver Island as well, but Google maps didn't let me add it to the route). Also, the big loop between Jasper and Banff isn't planned, it's just how Google calculated the route for some reason. As far as I know, it should be possible to get from one park to another by following the road that is between them (through the green parts). I could be wrong though