Styles change over time. The Stutz Bearcat was very stylish then, just as the Escalade is now, but either one would look awkward and out of place if you took it out of the context of the fashions of its time. Look at the modern and classic VW Beetle, Mini and Fiat. Those updated looks we prefer now will undoubtedly look as dated and clunky as their admired forbears do.
Imagining the question is not about the most faddish car, but the ones whose attractiveness has lasted longest, I'd go for the conventional Volvo P1800 and JagXKE, but for being unique faithful to its own fully-achieved aesthetic, hands down it's the Pacer, with the Innocenti perfection of the Mini a close, but safer second.