When gossiping about how Mariah Carey pulled her diva card and nearly tanked her performance at this year's Rockefeller Center tree lighting ceremony, don't forget that her first holiday album Merry Christmas celebrates its 20th anniversary this season! The disc, released in 1994 when Mariah was just 24 years-old, spawned arguably the most successful and universally loved contemporary Christmas song ever, 'All I Want for Christmas is You'.