When I first arrived in San Miguel, I stayed at another posada, but there was always noise (music, other guests) that interferred with my sleep. When I looked for an alternative, most all the other posadas were over $200, which is expensive for Mexico. Then I saw an ad in the local newspaper for Posada Corazon, and went to see it. Not only was it only two blocks from the central square in San Miguel, it was a private home in the middle of a lovely garden. Calm at last! It cost $90 (single) and had a beautiful bougainvillier vine growing on the terrace next to my room. Their library is well-stocked; it's like visiting a friend in San Miguel. And their breakfast was really excellent; they make their own bread.
Highly recommended!
