Amen, although it’s actually five, all nominated for Best Picture Oscars. Six, if you count Godfather Part III (not that you ought), in which he appears in archive footage.
Godfathers I & II
The Conversation
Dog Day Afternoon
The Deer Hunter
That’s a body of work and a half, so here’s to John Cazale.
Frances McDormand springs to mind:
*Burn After Reading
Miss Pettigrew Lives for a Day
Something’s Gotta Give
Laurel Canyon
Almost Famous
Wonder Boys
Primal Fear
Fargo
Short Cuts
The Butcher’s Wife
Barton Fink (voice) (uncredited)
Miller’s Crossing (uncredited)
Darkman
Mississippi Burning
Raising Arizona *
As does Kate Winslet:
Revolutionary Road
The Reader
Little Children
Romance & Cigarettes
Finding Neverland
Eternal Sunshine of the Spotless Mind
Iris
Enigma
Quills
Holy Smoke
Hideous Kinky
Titanic
Hamlet
Jude
Sense and Sensibility
Heavenly Creatures
I have to agree with this. It’s a surprise that Meryl Streep has a wonderful body of work? William Macy? Kate Winslet?
How about Katie Holmes? This isn’t a bad track record for someone considered a lightweight:
Thank You for Smoking
Pieces of April
The Gift
Wonder Boys
Go
The Ice Storm
I guess it depends on what you mean by “wonderful body of work.” If you simply mean “good movies that these actors have been in,” then sure Katie Holmes qualifies.
But i’ve seen three of those Katie Holmes movies, and in my opinion each one was good despite her presence, rather than because of it. Contrast that with the majority of Macy or Streep’s work, where their presence is often crucial to the overall quality of the movie.
I’ve noticed that, if a movie has Brad Pitt in it, it’s likely to be a pretty good ride.
How about Willem Defoe? The boy’s as ugly as homemade soap, but I’d pay good money to watch him read a phonebook.
Robert Duvall
Michael Sheen.
This is an actor who disappears into a role so completely that most folks would never associate any two of his roles with the same man.
Underworld: Rise of the Lycans (2009) … Lucian
Frost/Nixon (2008) … David Frost
Music Within (2007) … Art
Blood Diamond (2006) … Rupert Simmons
The Queen (2006) … Tony Blair
Very few people saw Music Within, but Sheen was astonishing as a brilliant man with Cerebral Palsy, and unrecognizably different in the Underworld films or as David Frost or Tony Blair.
Bruce Willis.
Bloody hell. I had to look him up and check that, but you’re right. I’d never have realised it was the same guy.
Sheen is phenomenol! I remember watching Underworld, and not even knowing who he was, and thinking, “That guy right there has IT.” He steals that movie right out from under the ‘stars’. And there’s more than a few Lucian fangirls who’re eagerly awaiting Rise of the Lycans right now. 
Billy Crudup was in Inventing the Abbots, Sleepers, Big Fish and Almost Famous.
And Auntbeast, I absolutely loved Tim Robbins in “The Pick of Destiny”.
Cate Blanchett
Add Oleanna to the William H. Macy list.