What are they?

Just to name a few:
Kevin Spacey- American Beauty and The Usual Suspects
Chris Farley- Tommy Boy
George Clooney- ER (I know it's a TV show), Ocean's 11
Harrison Ford- Presumed Innocent, Indiana Jones and the Temple of Doom
Catherine Zeta-Jones- Chicago
Renee Zellweger- Bridget Jones's Diary
Bonnie Bedelia- Presumed Innocent
Kirsten Dunst- The Virgin Suicides

Holly Hunter- Raising Arizona

Rachel Griffiths- Muriel's Wedding

Jessica Lange- Blue Sky

Johnny Depp- Benny and Joon, What's Eating Gilbert Grape, Pirates Of The Caribbean

Paul Newman- The Hustler, The Long Hot Summer

Nicholas Cage- Raising Arizona , Moonstruck

Jim Carrey- "The Mask", "The Cable Guy", "Truman Show", "Dumb and Dumber", "Lemony Snicket's" and "Me Myself and Irene".

Humphrey Bogart- "The Big Sleep".

Cary Grant- "The Charade" and "The Amazing Adventure".

Audrey Hepburn- "The Charade" and "Breakfast At Tiffany's".

James Stewart- "Made For Each Other".

I also like Katharine Hepburn's acting, but I haven't seen many of her films, so I don't have a favorite film that she's acted in yet. I have seen "The Philadelphia Story" and thought it was okay, but it's not one of my favorite films.

Mel Gibson--Braveheart, Conspiracy Theory
Julia Roberts--Steel Magnolias, Conspiracy Theory
Lily Tomlin--9 to 5, Incredible Shrinking Woman
Reese Witherspoon--Election, Cruel Intentions
Kiefer Sutherland--The Lost Boys
Gene Wilder--Young Frankenstein, Willy Wonka & the Chocolate Factory

That's it for now. There are so many more.

Christopher Lloyd - Back to the Future trilogy, Clue, and The Dream Team.

Michael J. Fox - Back to the Future trilogy.

Maculay Culkin - Home Alone 1 and 2, Richie Rich.

Robin Williams - Mrs. Doubtfire, Patch Adams.

Liza Minnelli - Arthur always makes me laugh

Judy Garland - The Pirate because she's playing a girl exactly like me

Gene Kelly - It's a Big Country for the best cameo/sweet love story ever told within five minutes

Bernadette Peters - Impromptu because she plays a really good villain

Grace Kelly - The Swan cuz she plays a princess and High Society cuz it's just wonderful :D

Johnny Depp: Blow,Chocolat,Pirates of the Caribbean.
Alicia Silverstone: Clueless,The Crush,True Crime
Tiffani Amber Thiessen: She Fought Alone,A Killer Among Frineds,Saved by the Bell: Wedding in Las Vegas
Julia Roberts: Pretty Woman,My Best Friend's Wedding
Julia Stiles: 10 Things I Hate About You,O,The Business of Strangers
Jennifer Love Hewitt and Sigourney Weaver: Heartbreakers
George Clooney: Oceans 12,Oceans 11,Out of Sight
Jake Gyllenhaal: Donnie Darko,The Day After Tommorow
Arnold Schwarzenegger: Jingle All the Way,Predator
Robin Williams: Mrs Doubtfire,Fathers Day
Kate Hudson: How to Lose A Guy in 10 Days,About Adam
Leelee Sobieski: My First Mister,The Glass House
Goldie Hawn: Overboard,First Wives Club,Town and Country,The Banger Sisters

Will Ferrell : Anchorman, Old School, Elf, A Night At The Roxbury, Zoolander, Superstar all the Austin POwers movies he's been in
Pauly Shore : Son In Law, Encino Man, IN the Army Now, Bio-Dome, Pauly Shore Is Dead
Adam Sandler : Happy Gilmore, Billy Madison, Anger Management, The Wedding Singer, The Waterboy, Big Daddy, Eight Crazy Nights
Ben Stiller : Dodgeball, Meet the Fockers,, Anchorman ( although he was only in one scene he was still awesome in it ) Meet the Parents, Zoolander, There's Something About Mary Starsky and Hutch, Along Came Polly
Vince Vaughn : Anchorman, Old School, Dodgeball, Be Cool,
Jack Black : School of Rock, Orange County, Shallow Hal
Steve Martin : Bringin Down the House, Father of the Bride, Father of the Bride 2, The Jerk, Man With Two Brains, LIttle Shop OF Horrors
JIm Carrey : Dumb and Dumber, both Ace Ventura movies, Man on the Moon, The Mask, Liar LIar, Cable GUy, Bruce Almighty
Cameron Diaz : THere's Something About Mary , Shrek and Shrek 2, the Charlie's Angels movies, The Mask
MIke Myers : The Austin Powers and Shrek movies and the Wayne's World ones
David Spade : Dickie Roberts, Tommy Boy, Black Sheep, Joe Dirt, its not a movie but 8 Simple Rules
Chris Farley : Tommy Boy, Black Sheep, Beverly Hills Ninja
Kirsten Dunst : The Spiderman movies, Bring It On
Owen and Luke Wilson
Owen : Meett he Parents Meet the Fockers, Zoolander, Starsky and Hutch
Luke : Old School, Anchorman , the Legally Blonde movies

And some more, as you can tell I like comedians LOL mostly, and Caemeron and Kirsten
Oh and

Drew Barrymore : CHarlie's Angels movies, Wedding Singer, 50 First Dates

Sissy Spacek:

Coal Miner's Daughter
Carrie
Violets Are Blue
Crimes of the Heart
Badlands

Drew Barrymore:

E.T.
Poison Ivy
The Wedding Singer
Riding in Cars With Boys

Jessica Lange:

The Postman Always Rings Twice (1981)
Frances
Sweet Dreams
Crimes of the Heart
Country

Johnny Depp:

Blow
A Nightmare on Elm Street
Edward Scissorhands
Benny and Joon
What's Eating Gilbert Grape
Ed Wood
Fear and Loathing in Las Vegas

Jack Nicholson:

Easy Rider
Five Easy Pieces
One Flew Over the Cuckoo's Nest
Chinatown
The Shining
Terms of Endearment
Broadcast News
A Few Good Men

Ed Harris:

Coma
Creepshow
The Right Stuff
Swing Shift
Places in the Heart
Sweet Dreams
Needful Things
Apollo 13
Pollock

Bill Paxton:

Weird Science
Near Dark
Tombstone
Apollo 13
A Simple Plan
Frailty

Holly Hunter:

The Burning
Raising Arizona
Broadcast News
Miss Firecracker
Always
Home for the Holidays
O Brother, Where Art Thou?

Jodie Foster:

Bob & Carol & Ted & Alice
Alice Doesn't Live Here Anymore
Taxi Driver
Freaky Friday (1976)
The Little Girl Who Lives Down the Lane
Carny
Foxes
The Hotel New Hampshire
Stealing Home
The Silence of the Lambs
Little Man Tate
Sommersby
Nell
The Dangerous Lives of Alter Boys

Paul Newman:

Somebody Up There Likes Me
The Long, Hot Summer
Cat on a Hot Tin Roof
The Hustler
Hud
Cool Hand Luke
Butch Cassidy and the Sundance Kid
The Sting
The Color of Money
Blaze
Road to Perdition

Hope Lange:

Peyton Place

The Best Of Everything

Death Wish

Nightmare On Elm Street 2

Anne Bancroft:

The Graduate

The Prisoner Of Second Avenue

Night Mother

Home For The Holidays

Shirley MacLaine:

Terms Of Endearment

Steel Magnolias

Nicole Kidman: To Die For, The Stepford Wives, The Hours, Dogville, Birth

Bette Midler: Ruthless People, The First Wives Club, The Rose, For the Boys, The Stepford Wives, Beaches, Outrageous Fortune

Katharine Hepburn: Adam's Rib, Pat and Mike, On Golden Pond, Guess Who's Coming to Dinner? (Not a fan of Woman of the Year)

Audrey Hepburn: Breakfast at Tiffany's, My Fair Lady, Wait Until Dark, A Nun's Story