The Memsahib and I have often pondered this question. Having had all sorts of weird and wonderful cars over the last 50 years or so, we keep coming up with the same answer - 1.6 Peugot 205 GTi.
Great fun car, 4 seats when needed, hatchback so plenty of luggage space for the 2 of us and it went like stink. Even had a ruddy great glass panel sliding sunoof if I remember correctly. My brother had the 1.9 version at the same time but it was nowhere near as nice to drive.
Sir P