Lake Louise is probably most famous not for the lake itself but the hotel named after it, the Chateau Lake Louise. One of the same family of Canadian Pacific Railway hotels that gave us the Banff Springs, the Chateau, as the name suggests, was modeled after the French building style; but if the hotel's the draw, your eye is quickly stolen by the surreal aquamarine waters of the lake itself, on the shores of which the Chateau rests. At the far end of the lake (perhaps an hour's hike on the Lakeshore Trail) the Victoria glacier hangs above the blue-green waters, preternatural and spectacular.
Lake Louise, the town, is 56km (35 miles) northwest of Banff, but leaves behind the crowded, touristy feel of its neighbor. It's small, for one thing, and nestled in trees. There is no main street, and it is an overall perfectly peaceful place. It also sits next to one of the largest ski areas in North America, and offers easy access to some of the most amazing trekking to be found in the park.
When you get to the Chateau, though, brave the crowds (this might be the only place in Louise you find them) and take a stroll along the Lakeshore Trail.
You can reach the glacier quickly and easily, then decide if you want to continue up toward Big Beehive (an aptly named rock formation above the lake) along the Plain of Six Glaciers Trail, to a teahouse where the beautiful view, with benefit of height, becomes otherworldly.