I wore Birki Pacifics for a while, but they stopped making them in regular (wide) width and they only come in medium (narrow) width now--I wore them soley because of comfort, and my last pair got stolen at a men's gathering (pseudo-camping in cabins).
I've tried Crocs, but I can never find them in my size, with one exception that were bright yellow, which I'm not about to wear. They seem really comfortable, possibly even more so than the Pacifics, but shoes in general are an item I'm not about to special order--foot comfort is very important to me as I am flat-footed.
The biggest advantage that they have is that they don't deteriorate or fit differently when wet.