A scene from Doctor Who

"Bow ties are cool."

In The Eleventh Hour.

In Meanwhile in the TARDIS 1.

In Amy's Choice.

In Vincent and the Doctor.

In The Lodger.

In The Big Bang. (Variation: "Fezzes are cool.")

In The Impossible Astronaut (Variation: "Stetsons are cool.")

In The Doctor's Wife (Variation: "Bunk beds are cool.")

In A Good Man Goes to War.

In The Girl Who Waited (Variation: "Glasses are cool.")

In The Snowmen.

In The Bells of St. John (Variation: "Monks (i.e., monastic robes) are not cool!")

In The Time of The Doctor (Variation: "Cool is not cool!")