"Happy Xmas (War is Over)," John Lennon, Yoko Ono and the Plastic Ono Band (Apple)

The most enduring result of John Lennon and Yoko Ono's public campaign for peace in the late 60s and early 70s is this classic 1971 single, originally released on clear green vinyl. Envisioned as peace propaganda by its creators, the record has taken on a life of its own as a Christmas staple. The fact that Phil Spector was co-producer may have had something to do with its success; in the Spector biography Out of His Head, there's a reference to Spector's coming in on a rehearsal of the song. Appalled by the skeletal backing group Lennon had assembled, he yelled, "Get me five acoustic guitarists. And if this is a Christmas record, we need bells...." Needless to say, covers of this iconic song are almost mandatory among those rockers who deign to make holiday discs.