Trimona sent me a sample of their Bulgarian yogurt and I loved it. This yogurt is made with strains of live cultures they say are unique to Bulgaria, and the yogurt is tangy and bright. It's also thinner, since they don't strain the whey out of the yogurt. This is the yogurt that reminds me most of the ultra-tangy homemade yogurt my mom used to make.
See their website for more info on where to find the yogurt. It's available in select retail outlets, including Whole Foods Market stores in the Northeast region, Balducci’s in Connecticut, Virginia and Maryland and many gourmet groceries in Manhattan, Brooklyn and Long Island.