San Miguel de Allende
When I think of San Miguel de Allende, I don't think first of its marvelous pink granite cathedral looking like an ornate candy sculpture, the storybook appearance of the main town, its unique Desert Ecology park a little up the hill, or its array of cultural choices for the midterm to long-term traveler. The weather there is typical of mountainous Mexico,ie, warm to hot in the day, cooler in the night, not especially humid. Its pleasant enough if you avoid the middday sun.
I think of it as a quiet town that is remarkably comfortable to the traveller and expatriate, one that is calm, quiet, and has a rhythm of its own. It's rhythm isn't of the Samba, or the Mexican hat dance. Its the beat of a quiet gentle drum marked by relaxing days in the town, and then a nighttime stroll before the pink granite church made in delicate and almost bizzare chiarrusco elements. The church is lit up, you sit down on the bench, and invariably someone will sit next to you and admire it. Then you'll say some words, they'll get up, and you can admire it some more.
It's a town for the independent mind, and comfortable enough for a whole community of expats to shape it into a different kind of place.
The 'rule of expats' can be marked in a lot of ways. There are courses for the bored expat, there are concerts, and a kind of sophistication that few Mexican towns have. The most marked, and one of the most important marks of its utility to travelers is the friendliness and usefulness of the Immigration office there. Its one of the easiest places to get a new Tourist card in all of Mexico. Why? People who go there usually don't go much further south than Oaxaca.
It's worth your while to go to San Miguel for visa problems, especially if the alternative is Mexico City. Of all the Immigration offices, Mexico city is one of the most bureacratic and hidebound of the bunch in Mid-mexico. What can take several days in Mexico City may be settled in a few hours in San Miguel. They get less demand, are used to foriegners, and so are gentler on the foriegner.
Besides, its a nice place to rest from more hectic Mexican cities, the climate is mild, and it can amuse you for a few days. Some people seem to be captured by it, so beware.