Two Virgins
The result of an all night session of musical experimentation; John Lennon and Yoko Ono's debut album Two Virgins is better known of the cover than any material contained within. The couple used a time delay camera to take nude photographs (the front cover displayed them frontally nude, and the rear cover featured their bare buttocks).
The cover provoked an outrage, prompting distributors to sell the album in a brown wrapper. Copies of the album were impounded as obscenity in several jurisdictions. Lennon wryly commented that the uproar seemed to have less to do with the explicit nudity, and more to do with the fact that the pair were rather unattractive. Nevertheless, the taboo breaking album cover was perhaps the first time that any male celebrity of any consequence had exposed himself so thoroughly to the public.