"The World is Mine" the dreamy music / love theme used to accompany the aerial sequences in "Strategic Air Command", a film made way back in 1954/55 is hard to beat.
Music was composed by long established Hollywood composer Victor Young (one of his last compositions – he died in 1956, a year after the film’s release).
Another favourite is "Apocalypse Now" and one of the best-known pieces of music of all-time "The Ride of the Valkyries" by Richard Wagner which plays as a U.S Army helicopter cavalry group charges in to eliminate a Viet Cong outpost.
A clip can be seen here:
Music starts about three minutes in.