So, where's the poll? Doesn't seem quite fair to lump any old foreign car against muscle cars. Is there some kind of common denominator, like the total initial cost?
I want the most bang for my buck with cars as well as PC. I would grab a 4dr version of a "Muscle" car, because it would have all the advantages of the muscle car, performance-wise, and very low initial cost. Same engine, tranny, linkage, brakes and general parts availability. Basically, I'd pick American V8, RWD for ruggedness and cheap, easy to install parts. More likely a Cadillac Fleetwood then a Chevy SS.
If I were to go for an import, at the same price point as American, I'd probably get a Parisian (Built in Canada)