Hitting theaters today is McG's This Means War, a frothy comedy that pits Chris Pine against Tom Hardy in the fight for Reese Witherspoon's smiley affections (best of luck there, Chris). From Arthurian legend to Bridget Jones's Diary, stories of smitten trios have flooded the popular landscape, each threesome casting its sinful shadow on boring old monogamy. For this list of 15 standouts, the door was open to hallucinations, inanimate objects, and even different species—which is not to say Ménage à Twilight was ever in the running.
Humphrey Bogart, Audrey Hepburn, and William Holden in Sabrina (1954). Billy Wilder's final Paramount film, which went on to a inspire a Sydney Pollack-directed remake, sees Audrey Hepburn play a chauffeur's daughter ever-pining for the prince (William Holden) of the family that employs her father. When she finally nabs her playboy's attention after going all Edith Piaf, he's already set to wed, and older bro Humphrey Bogart swoops in to avert disaster. Sparks fly faster than film noir bullets, and we say: Not a bad fallback.