I alternate between two towns, both excellent locations. From Blois, you can easily reach the chateaux of Blois (it's right downtown), Chambord, and Cheverny. From Tours, you can easily reach Amboise, Azay-le-Rideau, Chenonceau, Chinon, Le Clos Lucé, Langeais, Loches, or Villandry. Do note that we're not talking about major distances here – the two towns are 45 minutes from one another, both by car or train.