I took my first pair of Aetrex on a trip to Europe and have added several other pairs since then. They are my favorite for something a little nicer looking than a Birkenstock (speaking for the women's selection - not sure about men's)
I have a pair of leather slip on sneakers, a pair of thong sandals with a blackstrap, and for non-cobble-stone streets, a pair of wedges. I love them all. They have cork soles and great cushioning, but maintaining support for plantar fasciitis.
The ""[Jillian][1]" is probably the most common travel sandal for women, but they have a lot of options.