The best unisex panties I have found so far are Jockey "No Panty Line Promise" Tactel nylon bikini panties. You can find them at Jockey factory outlets, Kohls, JC Penneys and other department stores. The fit is absolutely perfect, like they were made for us!
Jockey "No Panty Lines Promise Tactel String Bikini" Perfect in every way for daily use. Nice fit and feel, and look great!