I swear by dansko clogs. But I recently discovered NOAT flat shoes:
http://www.naot.com/cgi-bin/show_product.pl?yaleet_number=11070&cat=11
Both Danskos and Noats are very expensive shoes, but they do wear very well. I swear I would never pay over $100 for a pair of shoes, but I see now that these shoes are worth every penny. My feet are happy...