Asics Onitsuka Tiger Serranos. It's like walking on a cloud, and they are really light. They also breathe moderately well for not having a bunch of high tech mumbo jumbo. Another plus is the fit, they work well with a variety of foot shapes, and are snug.
http://www.onitsukatiger.com/us/en-us/serrano/p/0010121688.9001
Pretty much defines the comfortable sneaker. They aren't meant for running, just walking and all day comfort. That being said, I know an avid runner that prefers this over anything Brooks, modern Asics, etc.