I've tried numerous canned chipotles over the past year, and La Torre is my favorite brand. The sauce is rich and flavorful, the peppers seem to have a slightly smokier and deeper flavor than other, more common supermarket brands.
I buy 'em at the local taqueria. Have never seen them in the local supermarkets, but they are available at a couple of the hispanic groceries in the area. They can be found on line as well. One source is: Amazon.com: La Torre Chipotle Peppers