Steve Jenkins, author of Steve Jenkins Cheese Primer, considers these sheep's-milk cheeses among the world's most important:

From France's Western Pyrénées: Ossau-Iraty (unpasteurized, so availability in the U.S. is rare) and the excellent non-A.O.C. pasteurized version available in the United States under the brand names Prince de Claverolle and Etorki.

From Corsica: Brindamour; also called Brin d'Amour

From Roquefort: Perrail or its brand name Louperac. This is the cheese the cheesemakers save for themselves. Eat it with a spoon!

From Italy: Pecorino Toscano, the sheep's-milk cheeses made in Tuscany.