San Martín de los Andes is the quieter, better-groomed cousin of Bariloche: a low-rise Andean town of timber buildings, mountain light, and cold blue water at the eastern end of Lago Lacar. It is touristy, certainly, but it has kept a village scale that makes it easier to like than many resort towns.
The town is the northern gateway to Lanin National Park and one end of the Seven Lakes route, the classic drive through forests, beaches, and glacier-cut lakes toward Bariloche. Close to town, Mirador Bandurrias, La Islita, and Lago Lacar give you good views without needing expedition gear.
Come for walking, kayaking, skiing at Chapelco, and the pleasure of returning each evening to a compact town with good chocolate shops and warm restaurants. It is less dramatic than southern Patagonia, but much easier to settle into.