3. adidas ZX 500

Year: 1984

It's tough to call the best ZX shoe and many will advance on this list, torch in hand, furious about the omission of the 380, 600, 700 and 800. But the adidas ZX 500 was a pioneering shoe in a number of ways: It set off the legendary ZX series of running shoes, but it also set the standard for the definitive running shoe alongside some efforts from New Balance and Nike. The father of a million styles, the 500 was made for high-mileage running and managed to merge technology with classic adidas looks, yet like plenty more from the class of 1984, it's curiously ageless, proving that this was the year that the running shoe formula was truly perfected.