Tom Cruise - Les Grossman
Known for: charming leading man roles. (Jerry Maguire, Risky Business) In Tropic Thunder: fat balding Hollywood executive with a short fuse.
Jim Carrey - Truman Burbank
Carrey's foray into drama. Before The Truman Show: quirky, slapstick characters. (Dumb and Dumber, The Mask)
Johnny Depp - Edward Scissorhands
The first of Depp's many eccentric characters. (Ed Wood, Fear and Loathing in Las Vegas) Before Edward Scissorhands: perceived as a teen heartthrob. (21 Jump Street, Cry-Baby)
Robin Williams - Walter Finch
Known for: quirky comedic and tearjerker dramatic roles. (Dead Poets Society, Mrs. Doubtfire) In Insomnia: calculated murderer and sociopath.
Tom Hanks - Forrest Gump
Hanks' foray into serious drama. Before Forrest Gump: comedy and romance. (A League of Their Own, Sleepless in Seattle)
Heath Ledger - The Joker
Known for: romantic leading men roles. (10 Things I Hate About You, A Knight's Tale) In The Dark Knight: psychotic mass-murdering villain.
Robert Downey Jr. - Kirk Lazarus
Known for: playing white men. (Iron Man, Kiss Kiss Bang Bang) In Tropic Thunder: an Australian with plastic surgery.
Liam Neeson - Henri Ducard
Known for: good guy roles. (Schindler's List) In Batman Begins: unforgiving villain.
Denzel Washington - Alonzo Harris
Known for: morally upstanding characters. (Philadelphia) In Training Day: morally bankrupt police detective.
Nicolas Cage - Charlie/Donald Kaufman
Known for: taking bad roles. (Gone in Sixty Seconds, National Treasure, The Wicker Man, Ghost Rider, Next, Bangkok Dangerous, Knowing) In Adaptation: not one, but two good roles.