Can raw-milk cheeses be legally sold in the United States? Yes, says mimosa, who owns a cheese shop in San Diego, but only if they have been aged at least 60 days. Raw-milk cheeses are widely available in the United States, both domestic and imported.
Still, your American cheese experience might not compare to cheeses you consumed during your Italian vacation, for a variety of reasons. Some cheeses are very regional, and are produced in quantities too small to allow for substantial export. Also, in all fairness to the cheeses of America, you were on vacation—everything tasted better.
Parmigiano-Reggiano is a special case. The rules for production are pretty firm, so if you’re getting bona fide Parmigiano-Reggiano certified by the DOC, variation should be minimal. However, it’s sold at a variety of ages, from 12 months to five years, and the younger the cheese, the less complex, says cheesemonger, a former cheese shop owner. Also, cheese will never improve after the first time you cut into it—it slowly degrades with exposure to air.
Board Links: U.S. cheese rules–pasteurization, etc.