Name some of the best acting performances you 've ever seen.

Kevin Bacon in 'Murder in the First'
Tarra Steele in 'Mockingbird don't sing'
Anne Hathaway in 'Les Miserables'

There's more, but these pop up right now.

Ewan McGregor in "Trainspotting"
Hugo Weaving in "V for Vendetta"
R. Lee Ermey in "Full Metal Jacket"
Malcolm McDowell in "A Clockwork Orange"
As you've said, Heath Ledger in "The Dark Knight"
These are the ones I can think of.

Shirley Temple in "Now And Forever"
Vivien Leigh in "Gone With The Wind"
James Stewart in "It's A Wonderful Life"
Shirley Temple in "Kathleen"
Daniel Radcliffe in "Harry Potter"
Shirley Temple in "Bachelor And The Bobby-Soxer"
Shirley Temple in "Little Miss Marker"
Emma Watson in "Harry Potter"
Rupert Grint in "Harry Potter"
Michael Gambon in "Harry Potter"
Tom Felton in "Harry Potter"
Cary Grant in "Arsenic And Old Lace"
Natalie Wood in "Rebel Without A Cause"
James Dean in "Rebel Without A Cause"
Natalie Wood in "Miracle on 34th Street"
Edmund Gwenn in "Miracle on 34th Street"
Anthony Perkins in "Psycho"
Joan Fontaine in "Suspiction"
Hattie McDaniel in "Gone With The Wind"
Shirley Temple in "Bright Eyes"
Carrie Fisher in "Star Wars"
Harrison Ford in "Star Wars"
Shirley Temple in "Stowaway"
Alice Faye in "Stowaway"
Robert Young in "Stowaway"
Shirley Temple in "Little Colonel"
Shirley Temple in "Wee Willie Winkie"
Shirley Temple in "Heidi"
Kate Maberly in "The Secret Garden"
Fairuza Balk in "Imaginery Crimes"
Elisabeth Moss in "Imaginery Crimes"
Johnny Depp in "Pirates Of The Carrebean"

not much of a, Val Kilmer fan, but he should have won an Oscar for his portrayal as, Doc Holliday in Tombstone

Ewan McGregor in Trainspotting
Heath Ledger in The Dark Knight
Kevin Bacon Flatliners
Anthony Hopkins Silence of the Lambs
Johnny Depp Pirates of the Caribbean
Christina Ricce Addams Family
Russel Crowe Master and Commander
Robert Downey Jr Sherlock Holmes
Christoper Waltz Inglorious Basterds
Hugo Weaving V for Vendetta
Christopher Walken The Deer Hunter