Board Thread:Wiki-Related Questions and Answers/@comment-4975807-20130603204447/@comment-3440938-20180406213057

Best Big Bad
 * 1) Regina Mills
 * 2) Cora Mills
 * 3) Tamara and Greg
 * 4) Peter Pan
 * 5) Zelena
 * 6) Ingrid
 * 7) Rumple and the Queens of Darkness*
 * 8) Emma Swan
 * 9) Nimue
 * 10) Hades
 * 11) Evil Queen
 * 12) Fiona
 * 13) Drizella
 * 14) Rapunzel Tremaine
 * 15) Gothel

or

Best story arc (Which somewhat fits into Best Big Bads/also some arcs aren't as defined as others such as season 1 and 2)
 * 1) The Curse arc? (Season 1)
 * 2) The Magic is Coming Arc (Season 2A)
 * 3) The Home Office Arc? (Season 2B)
 * 4) The Neverland Arc
 * 5) The Oz Arc
 * 6) The Frozen Arc
 * 7) The Queens of Darkness/Happy Ending Arc
 * 8) The Dark One/Camelot Arc
 * 9) The Underworld Arc
 * 10) The Land of Untold Stories/Serum Queen Arc
 * 11) The Final Battle Arc
 * 12) The Cinderella Arc
 * 13) The Coven of the Eight/Final Arc