One of the most spectacular drives in Canada...
Travel west on Highway 1 to Canmore. (Pay $10/car/day to enter Banff National Park.) Highway 1 will take you into the heart of the Rocky Mountains through the town of Banff. From there, you can continue straight onto Lake Louise.
Better yet, turn off to the right shortly after Banff and drive the winding, forested Bow Valley Parkway, which will take you to Johnston Canyon (Have the time? Take a hike!) Then continue through Lake Louis townsite, then through to where the Icefields Parkway (Hwy 93) branches off towards Jasper.
You can cut the loop short by turning onto the more remote David Thompson Highway (Hwy 11) at Saskatchewan Crossing (about halfway between Lake Louis and Jasper) to Red Deer then back to Calgary.
If you continue north to Jasper, expect long stretches of UNBELIEVABLE views! Unfortunately, these views mean heavy gridlock during the summer months. (Once in Jasper, it is about 250 miles back to Calgary.)