Here are some actors and what I consider their top 5 best performances(Be it Main actor or Supporting) I can't wait to read your replies and choices-:)

Harrison Ford

1)The Mosquito Coast
2)Witness
3)Frantic
4)Star Wars
5)Raiders of the Lost Ark

Clint Eastwood

1)In The Line of Fire
2)Unforgiven
3)Million Dollar Baby
4)Dirty Harry
5)The Outlaw Josey Whales

Ed Harris

1)Pollock
2)Jackknife
3)The Human Stain
4)GlenGarry GlenRoss
5)Gone Baby Gone

Tommy Lee Jones

1)In The Valley of Elah
2)JFK
3)Cobb
4)The Fugitive
5)Natural Born Killers

Robert DeNiro

1)Godfather II
2)Raging Bull
3)Taxi Driver
4)Midnight Run
5)Casino

Al Pacino

1)Godfather II
2)Scarface
3)Serpico
4)Dog Day Afternoon
5)Scent of a Woman

Gene Hackman

1)The Conversation
2)The French Connection
3)Unforgiven
4)The Royal Tenenbaums
5)Superman

Dustin Hoffman

1)Midnight Cowboy
2)Kramer vs. Kramer
3)Lenny
4)Tootsie
5)Rain Man

Robin Williams

1)Good Will Hunting
2)Good Morning Vietnam
3)Dead Again
4)Awakenings
5)The Final Cut

George C. Scott

1)Patton
2)Doctor Strangelove
3)The Changeling
4)Fire Starter
5)Exorcist III

Gregory Peck

1)To Kill a Mockingbird
2)MacArthur
3)The Omen
4)Cape Fear(The Original)
5)Other People's Money

Paul Newman

1)The Verdict
2)Cool Hand Luke
3)The Sting
4)Road to Perdition
5)Nobody's Fool

Bruce Willis

1)12 Monkeys
2)The Sixth Sense
3)Die Hard
4)Unbreakable
5)Hostage

Anthony Hopkins

1)The Remains of the Day
2)The Silence of the Lambs
3)Shadowlands
4)Audrey Rose
5)The World's Fastest Indian

Sean Penn

1)Mystic River
2)Dead Man Walking
3)Sweet and Low Down
4)Casualties of War
5)Fast Times at Ridgement High

Michael Douglas

1)Traffic
2)Wonder Boys
3)The American President
4)Wall Street
5)Romancing the Stone

Tim Robbins

1)The Shawshank Redemption
2)The Mystic River
3)The Player
4)Bull Durham
5)Cadillac Man

Morgan Freeman

1)The Shawshank Redemption
2)Million Dollar Baby
3)Driving Miss Daisy
4)Nurse Betty
5)Glory