The ClO4, BF4, and ReO4 salts of BDT-TTP, 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene, are isostructural, having uniform columns of the donor molecules. These salts are essentially metallic down to low temperatures, though the resistivity increases to some extent below 200 K. The thermoelectric power and ESR show simple metal-like behavior down to low temperatures.