1953 Chevrolet Corvette
The first American "sports car" to be mass produced. This car led directly to the Ford Thunderbird, and more importantly, the Ford Mustang, which in turn set off the "personal car" sales surge of the '60s. Aside from the ground-breaking debut of the Corvette, you're all already familiar with the exceptional success of the Corvette with every revision since then in terms of sales figures, motorsports success, and prestige. (okay, maybe not so much with the late C3 and early C4s that suffered horribly from growing pains due to the new emissions standards)