My favorite mad ones

As: The Joker
At: The Dark Knight

As: Elisabeth Burrows
At: Don't Say A Word

As: Daisy Randone
At: Girl, Interrupted

As: Billy (age 18)
At: Silent Night, Deadly Night

As: Rhoda Penmark
At: The Bad Seed

As: Carol
At: Repulsion

As: Kevin (teenager)
At: We Need to Talk About Kevin

As: Kevin (6 to 8 years old)
At: We Need to Talk About Kevin

As: Kevin (Toddler)
At: We Need to Talk About Kevin

As: Anton Chigurh
At: No Country for Old Man

As: Annie Wilkes
At: Misery

As: Violet Weston
At: August: Osage County

As: Jack Torrence
At: The Shining

As: Lisa Rowe
At: Girl, Interrupted

As: Donnie Darko
At: Donnie Darko

As: Aileen (And the real Aileen too)
At: Monster

As: Bellatrix Lestrange
At: Harry Potter series

As: Dr. Hannibal Lecter
At: The Silence of the Lambs (And also at Hannibal and Red Dragon)

As: Corky Withers / Fats
At: Magic

As: Eric Draven
At: The Crow

As: Tiffany
At: Silver Linings Playbook

As: Pat
At: Silver Linings Playbook

As: Travis Bickle
At: Taxi Driver

As: Herself
At: Specially Scream Queens (reality show)

As: Esther
At: Orphan

As: Norman Bates
At: Psycho (and also at Psycho II and Psycho III)

As: Mark Lewis
At: Peeping Tom

As: Jacob
At: Jacob's Ladder

As: Carrie
At: Carrie

As: Jasmine
At: Blue Jasmine

As: Hayley Stark
At: Hard Candy

As: Maria Elena
At: Vicky Cristina Barcelona

As: Sweeney Todd
At: Sweeney Todd: The Demon Barber of Fleet Street

As: Elizabeth
At: Prozac Nation

As: Leland P. Fitzgerald
At: The United States of Leland

As: Lars Lindstrom
At: Lars and the Real Girl

As: Mrs. Mott / Peyton Flanders
At: The Hand that Rocks the Cradle