Tia and Tamera Mowry and Mary-Kate and Ashley Olsen
Double trouble! When the Olsen twins were on Full House, older twins and Sister, Sister stars Tia and Tamera Mowry babysat them! Years later, when asked who would win a "cage match" on CNN in 2012, the Mowry sisters said: "They are amazing. But I think we would definitely kick their butts!"