Comfiest ones I ever got in my life were at Payless! They didn't last long though.

Target Camberwell (note: must be Camberwell, they seem to have a good buyer there) often have amazing shoes, better than other stores.

AND I will have to check what my work shoes are. I bought them second hand in 2008 and they are still going. I think they might be Diana Ferrari supersoft? Will have to check though, I keep them at work. They are soooo comfy, and obviously very long lasting.