NSFW! In 1970s Times Square, even the libraries were sleazy.

(click ad for closer look)
Nowadays, the scariest sights in midtown NYC are skyscrapers with targets on them, or badly-rendered Bill Clinton dolls, or questionably-positioned Sumo wrestlers, or huge animated M&Ms making hooker-faces at you. The few remaining smut outposts are overshadowed by huge Mary Poppins' billboards totally softening your hard-on.
So let's return to the middle of 1976 Manhattan...to rush-hour muggings on 42nd Street, to aggressive peep show barkers, to daily skirt-lifting prostitute vagina and jerking-off street man penis sightings...to "The Library" massage parlor, which was just a block north of the actual New York Public Library. "Complete Satisfaction" for 10 bucks—all gratuities included! Take that, Dewey Decimal! (image source)