My first car was a 1977 Olds Cutlass Brougham 4-door 350 (with a blazing ~160 hp).
Oh yeah. Pillow-top plaid velour seats and a soft top. It was as old as I was, with 70K original miles. Great rolling couch until the transmission quit. The Beretta age began.
Most efficient:
1997 Honda Civic DX Coupe. No A/C or PS, 5-speed, 106 hp 1.6L. The lack of extra options made it a light, fun car with the benefit of about 30-40 mpg. The horsepower wars began and I enlisted (1999 Civic Si Coupe).
-Rick