The term "geek chic" was probably invented for Winnie Cooper.  Before she appeared on our TV screens with her glossy brown hair, high-waisted flares, never-ending collection of checked shirts, and big, big brain, "smart" meant wearing a Math Olympiad t-shirt and hoping for the best.  Winnie even made turtlenecks look cool. (And eventually, algebra too - thanks Danica McKellar!)  When she stole Kevin Arnold's heart, she stole ours, too...