The 144 mile drive from Lake Louise to Jasper is one of the most beautiful in the world. Allow all day; there are multiple stops, including Crowfoot Glacier viewpoint, Bow Lake viewpoint, Peyto Lake viewpoint, Columbia Icefield, Sunwapta falls, and Athabasca falls. You need to do this at least once in your life.
You might consider the Gypsy app for this (audio tour of the parkway on your phone).
Get the Parks Canada download for the parkway before you go as well.