Heath Ledger's Joker from The Dark Knight [which is also my favorite movie].

Spawn
from..Spawn

Percy/The Scarlet Pimpernel and also Marguerite and oh hell Chauvelin from THE SCARLET PIMPERNEL...Chauvelin moreso from the films & musical!

Walter Hartright in Woman in White

Jane Eyre in Jane Eyre !

Ivan Drago (Rocky IV)

The girl in Generation X (can't remember her name):o

Johnny Depp as Jack Sparrow - Pirates of the Caribbean trilogy.
Geoffrey Rush as Barbossa - Pirates of the Caribbean trilogy.
Russell Crowe as Maximus - Gladiator.
Adrien Brody as Noah Percy - The Village.
Joaquin Phoenix as Jack Morrison - Ladder 49.
Gerard Butler as King Leonidas - 300.
Gary Oldman as Sirius Black - Harry Potter and the Prisoner of Azkaban.
Robert Pattinson as Cedric Diggory - Harry Potter and the Goblet of Fire.
Timothy Spall as Wormtail - Harry Potter and the Prisoner of Azkaban.
Brad Pitt as Achilles - Troy.
Matt Damon as Jason Bourne - Jason Bourne trilogy.
Leonardo DiCaprio as Danny Archer - Blood Diamond.
Leonardo DiCaprio as Billy Costigan - The Departed.
Jack Nicholson as Costello - The Departed.
Al Pacino as Walter Burke - The Recruit.
Colin Farrell as James Douglas Clayton - The Recruit.
Daniel Stern as Marv Merchants - Home Alone 2: Lost in New York.
Martin Lawrence as Miles Logan - Blue Streak.
Martin Lawrence as Malcolm / Big Momma - Big Momma's House and Big Momma's House 2.
Martin Lawrence as Detective Marcus Burnett - Bad Boys II.
Martin Lawrence as Roy McCormick / Preacher Don - Rebound.
Martin Lawrence as Terrance Paul Davidson - Nothing to Lose.
Jim Carrey as Bruce Nolan - Brunce Almight.
Jim Carrey as Count Olaf - Lemony Snicket's A Series of Unfortunate Events.
Jim Carrey as Fletcher Reede - Liar Liar.
Jim Carrey as The Cable Guy - The Cable guy.
Jim Carrey as Ace Ventura - Ace Ventura: When Nature Calls and Ace Ventura: Pet Detective.
Heath Ledger as The Joker - The Dark Knight.
Keanu Reeves - The Constantine.
Oliver Reed - Proximo - Gladiator.
Aamir Khan - Ghajini.
Asin - Ghajini.

joey from friends xD

Afro Samurai.

Malcom Reynolds played by Nathan Fillion in the series Firefly and the movie Serenity. Best character ever. Badass.

TV
Penny from The Big Bang Theory

Movie
Russel Coight from Russell Coight's Celebrity Challenge. Yes, it's a telemovie, but still a movie.

Book
Scarecrow from various books by Matthew Reilly.

Gambit from X-men.
Fred and George from Harry Potter
Foxxy Love from Drawn Together
Tom Sawyer from, emm, try to guess xD
Holden Caulfield from The Catcher in the rye

Robert Carlyle as Dr. Rush in SGU.

Netyri played by Zoe Saldana from AVATAR
Jake Sully/JakeSuully played by Sam Worthington from AVATAR
Dr. Horrible played by Neil Patrick Harris in Dr. Horrible's Sing-along-blog
The Music Meister played by Neil Patrick Harris
The Joker played by Heath Ledger in The Dark Knight

Benjamin Linus - LOST
The Emperor - Star Wars (IV, V, VI)
Dr. Manhattan - Watchmen
Dexter Morgan - Dexter

Red Foreman from That 70s Show.
Tony from NCIS
Dr. House from House.

One of my current favorites is Sue Sylvester from Glee. She's the one I love to hate sometimes.

Jack a.k.a Jackie (Sean Hayes) on Will and Grace

TV show - Cartman from SouthPark, because he's such an asshole.
Movie - Zia (played by Patrick Fugit) from Wristcutters: A Love Story, because he's adorable.
Book - Holden Caulfield from The Catcher in the Rye, because he's a psychomaniac.

TV.
Dr. John Dorian - Scrubs.
Earl Hicey - My Name is Earl.
Chandler Bing - Friends.
Sam & Dean Winchester - Supernatural.
Gene Hunt - Life on Mars/Ashes to Ashes.
Old Gregg - The Mighty Boosh.
The Cockney Hitcher - The Mighty Boosh.

Film.
The Joker - The Dark Knight.
Ace Ventura - Ace Ventura.
Stuart Shepard - PhoneBooth.
The Caller - PhoneBooth.
Bruce - Finding Nemo. [FISH ARE FRIENDS, NOT FOOD!]
Napoleon Dynamite - Napoleon Dynamite.
Pedro - Napoleon Dynamite.
Ron Burgandy - Anchorman.
Chazz Michael Michaeals - Blades of Glory. [I'll get IN your face!!]
Shaun - Shaun of the Dead.