Did the drive from Jasper to Lake Louise. It takes most of the day so plan ahead as others mentioned (not too many places to eat). Amazing how you just keep driving and are constantly surrounded by amazing scenery, eventually stopped taking pictures because there was so much :)
Pick a few key points to stop for a hike or other attraction, the day goes fast so there is only so much you can fit into one drive. We did Athabasca Falls, Sunwapta Falls, Columbia Icefield walk on the glacier, and Peyto Lake. Along with many stops for photos. It was very cloudy most of the day for us, but even with that it was still beautiful.
Can't recommend enough, easily one of the most scenic drives I have ever taken.