Introduced in 1964 to get boys used to the idea of fighting in Vietnam when they grew up, G.I. Joe is the bestselling boys' doll of all time (though he is marketed as a "movable fighting man").
Unfortunately, when you took his clothes off, you got this:
Barbie's "boyfriend" Ken, introduced in 1961, was more fun. He came wearing a swimsuit, with a natural-looking body that got more buff as time passed:
Unfortunately, no letter to Santa Claus or picture circled in a toy catalog ever produced a Ken doll. Your sister or the girl down the block certainly had one, but she always wanted to play "Barbie and Ken at the prom."
See also: The Big Men of American Tall Tales