The adidas Samba was introduced as a football (no, the other one) training shoe way back in 1950, giving it a multiple-decade head start over more or less every other football trainer to follow. It's slim lines and gum outsole have been copied countless times, and it also served as the forebear to adidas's skate line. Plus, more or less every person on the planet has owned a pair of Sambas at one time or another. Just ask them.
5. adidas Samba