King also had a great cameo in his terrible '80s movie Maximum Overdrive.
I think Bogart was kind of involved in other projects at the time that movie was made. Was it archive footage?
He got quite a lot of screen time for a cameo. He was a pretty major character that showed up more than once in the movie. I like how the 7th Harry Potter movie stole the part where he gets attacked by swirling paper.
Nitpick: Freeman has a speaking role in Hot Fuzz. (He plays Simon Pegg’s London superior.) His very, very brief cameo was in Shaun of the Dead.
Watch out for that there Swirling Paper. It gets mighty ornery.
The record might be held by Into the Night, a rather slight effort by John Landis. To quote Wikipedia, the cameos include:
John Landis appears in the film himself as the mute member of the quartet of Iranian henchmen, alongside:
Jack Arnold, director of science fiction films, including It Came from Outer Space (1953), as the man with the dog in the elevator.
Rick Baker, Academy Award-winning make-up artist on An American Werewolf in London (1981), as the drug dealer.
Paul Bartel, director of low-budget films, including Eating Raoul (1982), as Beverly Wilshire Hotel Doorman.
David Cronenberg, director of body horror films, including Shivers (1975) and Rabid (1977), as Ed’s supervisor in the boardroom.
Jonathan Demme, who at the time had directed a number of lower-budget and exploitation films, as the thin federal agent with glasses.
Richard Franklin, Australian director of Roadgames (1981), as the aerospace engineer sitting next to Herb in the cafeteria.
Carl Gottlieb, who co-wrote Jaws (1975), as the large federal agent with moustache.
Amy Heckerling, director of Fast Times at Ridgemont High (1982), as “Amy”, the clumsy waitress.
Jim Henson, creator of The Muppets, as the man on the phone talking to ‘Bernie’.
Colin Higgins, who wrote Harold and Maude (1971) and directed The Best Little Whorehouse in Texas (1982), as the actor in the hostage film.
Lawrence Kasdan, writer and director of Body Heat (1981), as the police detective who interrogates Bud.
Jonathan Lynn, co-writer of Yes, Minister, as the tailor who fits the SAVAK agents.
Paul Mazursky, director of Bob & Carol & Ted & Alice (1969) and An Unmarried Woman (1978) as Bud Herman, the beachhouse owner and accused drug dealer.
Carl Perkins, rockabilly musician and composer of ‘Blue Suede Shoes’, as Mr. Williams.
Daniel Petrie, director of A Raisin in the Sun (1961), as the director of the hostage film.
Dedee Pfeiffer, actress and sister of Michelle Pfeiffer, as the hooker.
Waldo Salt, Academy Award-winning screenwriter of Midnight Cowboy (1969) and Coming Home (1978), as the derelict who informs Ed of his car having been towed.
Don Siegel, director of Invasion of the Body Snatchers (1956) and Dirty Harry (1971), as the man caught with a girl in the hotel bathroom.
Jake Steinfeld has a small role as “Larry,” Jack Caper’s bodyguard.
Roger Vadim, director of And God Created Woman (1956) and Barbarella (1968), as Monsieur Melville, the French kidnapper.
Well, it would kinda half to be. 
Was funny amid the other cop/crime movie character cameos, at least until they overextended the dialogue.
It has been awhile since I’ve seen Brazil. But you are right…DeNiro is a cameo more in the sense of “big name actor” playing small part in otherwise WTF? movie than cameo “of hey, its thats famous guy for 5 seconds if you look quickly”.
Along those lines…I seem to recall a serious B list movie called Space Truckers? Dennis Hooper was in it.
I said on more than one occasion. If you don’t watch Brazil and Office Space and don’t find both of them both funny AND blood pressure inducing…well, you haven’t been in the real word long enough.
+2.
OTOH, I know many people who put Idiocracy in the same category and even though much of it squarely targets my area of professional interest, I find it utterly tedious.
The only belly laugh in it for me was the clock tower flashing 12:00, but that was a techy joke.
True, but his role in Hot Fuzz is so brief it almost counts.
Speaking of Simon Pegg, he had a cameo in Nick Frost’s Cuban Fury, driving past a parking garage confrontation.
One of the very few current pop groups I’ve heard of, Of Monsters and Men, did a cameo as medieval musicians in the Game of Thrones episode where Arya was watching the play about the Lannisters.
Two from the 40s:
Walter Huston as Captain Jacobi in The Maltese Falcon. He delivers the Falcon to Sam Space and immediately dies. I’m not sure if he actually has a line.
Athlete Jim Thorpe in White Heat. He plays a convict in the classic scene when Cody learns his mother is dead. Thus news is passed by having each convict at the dining table whisper it to the next. Thorpe is halfway down the line; he is shown twice.
Which led to the great meme of George C. Scott reacting to screenings of Adam Sandler movies.
Anyway, back on topic, Hunter Thompson is another author who made a quickee appearance in a movie based on one of his books. In the Gilliam/Depp version of “Fear and Loathing in Las Vegas”, while Duke is having his flashback to a Jefferson Airplane concert, he has an acid vision of himself as an old man at the club. The ‘old man’ is the real Thompson.
David Bowie as Nikola Tesla
I thought he was editor of the school newspaper. Either way, not metal.
Somebody once sent minister Henry Ward Beecher a letter in which the address included Beecher’s name followed by “D D” (for “Doctor of Divinity”). Beecher drew a dash between the D’s and sent it back. 
A Pee Wee movie? Pee Wee’s Big Adventure is THE Pee Wee movie. And arguably Tim Burton’s best (at least in the top 5.) Also has cameos by James Brolin, Morgan Fairchild, and Godzilla.
The original Naked Gun movie had a lot of athletes and sports announcers in it, including Reggie Jackson, Dick Vitale, Dick Enberg, Jim Palmer, Mel Allen, Curt Gowdy, and Tim McCarver. (With Dr. Joyce Brothers, as a baseball announcer)
I stand corrected!
Star Trek VI had a weird cameo from Christian Slater. It was weird, because the way it’s set up - Kirk’s asleep in his quarters when he hears someone at the door. He tells them to come in, and the door opens to show a figure silhouetted by the lights in the hallway. Kirk turns on the lights in his room, and OH MY GOD IT’S CHRISTIAN SLATER!
…was the reaction of absolutely nobody in the theater.