After auditioning as solo acts for The X Factor in the U.K., five boys joined forces to inflict upon an unsuspecting public their PG-rated paeans, garnering both Mom’s approval and waves of teenage puppy love. Dress code: Safe. One’s first impulse is to reward them with treats. Dance party: Lots of energetic, aimless strutting, à la Menudo. Fan base: Directioners, as their unruly fans are known, have succumbed to everything from fainting spells to an inability to stop shrieking—hence the band’s reported 100-strong security detail.