Someday by The Strokes (Letterman, 2002)

Someday I'll write at great length about how I think this song is among the best say, five? songs ever recorded. Certainly a top three since entering our current millennium.

It's perfect beyond measure and this Letterman performance is also perfect in its own way. Trigger warning for the born before 1995 crowd, the nostalgia from this video could very well physically pain you.