Which line is a repeated catchphrase in the “Die Hard” film franchise?

The one-liner "Yippee Ki Yay, ..." is one of John McClane's (played by Bruce Willis March 19, 1955) most famous lines. It was voted #96 of "The 100 Greatest Movie Lines" by Premiere magazine in 2007.

It was heard in the original "Die Hard" movie in 1988, and “Yippee-ki-yay, ...,” is one of the many one-liners that have graced the action film, a body of work not known for its strong verbal tradition. Indeed, the delivery of the one-liner ranks among the most cherished rites of this ritualistic genre. Whether a quip, catchphrase, or callback to an earlier installment in a franchise, one-liners, even at their corniest, provoke the same glee as the most pyrotastic action sequences.

John McClane frequently says it to taunt his adversaries, or in the moments before killing them.

The catchphrase "Yippee-ki-yay, ..." was inspired by western actor Roy Rogers's (born Leonard Franklin Slye, November 5, 1911 – July 6, 1998), own "Yippee-ki-yay, kids". Roy Rogers was an American singer, actor, and television host.