Martin and Lewis have over a dozen.
Willam Powell & Myrna Loy: 14
- Manhattan Melodrama (1934)
- The Thin Man (1934)
- Evelyn Prentice (1934)
- The Great Ziegfeld (1936)
- Libeled Lady (1936)
- After the Thin Man (1936)
- Double Wedding (1937)
- Another Thin Man (1939)
- I Love You Again (1940)
- Love Crazy (1941)
- Shadow of the Thin Man (1941)
- The Thin Man Goes Home (1944)
- Song of the Thin Man (1947)
- The Senator Was Indiscreet (1947)
The obvious ones have been taken already
Dean Martin and Frank Sinatra:
Some Came Running
Ocean’s 11
Pepe
Sergeants Three
The Road to Hong Kong
Come Blow Your Horn
Four for Texas
Robin and the Seven Hoods
Marriage on the Rocks
Cannonball Run II**
*cameos
Lotta numbers in those titles – 2, 3, 4, 7, 11
Only if you count those THIN MAN movies, which the OP says is no-go.
This is an old, old example, but Janet Gaynor and Charles Farrell starred in 12 movies together, from the silent era to the talkies:
7th Heaven (1927)
Street Angel (1928)
Lucky Star (1929)
Happy Days (1929)
Up (1929)
High Society Blues (1930)
The Man Who Came Back (1931)
Merely Mary Ann (1931)
Delicious (1931)
The First Year (1932)
Tess of the Storm Country (1932)
Change Of Heart (1934)
They were also romantic partners off-screen for most of that time, and you can see it in their performances. More proof
Wes Anderson has so many recurring collaborators that his Wikipedia page has a section to show who has worked on which films. Wes Anderson - Wikipedia
Bill Murray and Owen Wilson have done six Anderson films together. Willem Dafoe, Adrian Brody, Waris Ahluwalia, Seymour Cassel, Willem Dafoe, and Anjelica Huston were in three movies each with Murray and Wilson. Kumar Paliana was in three with Murray and four with Wilson.
All three Wilson brothers acted in Anderson’s first three films.
Etc. That’s without checking to see if any of them were in other movies together, and I also could have easily gotten one or two numbers wrong for some of them. For example, I think Luke and Owen Wilson have been in at least five movies together.
Kenneth Williams worked with Sid James 17 times,
Kenneth Williams worked with Joan Sims 22 times,
Sid James worked with Joan Sims 17 times,
All three worked with Charles Hawtrey in 14 films,
detailed here.
Carry On was a series and excluded by the OP.
Bela Lugosi and Lon Chaney, Jr.:
The Wolf Man (1941)
The Ghost of Frankenstein
Frankenstein Meets The Wolf Man
Abbott and Costello Meet Frankenstein
The Black Sleep
You still get 9, even if Manhattan Melodrama only had Myrna Loy in a small role.
I’m pretty sure most of those were related/series.
Will Farrell and Steve Carell were both in Anchorman and Anchorman 2, as well as Bewitched.
Paul Rudd was also in Anchorman, and appeared with Carell and Seth Rogan in The 40 Year Old Virgin. Rudd and Carell were also in This Is the End.
You know what? Screw it. Paul Rudd, Will Farrell, Steve Carell, Leslie Mann, Elizabeth Banks, Seth Rogan, Jonah Hill and others all interact in different movie series all the time, usually with Judd Apatow involved somehow. I don’t have the time to make a flow chart right now.
Fair enough, but this isn’t GQ. As a Cafe Society thread I consider my post to be interesting and not breaking any rules.
"Who else has starred together four or more times, where the movies weren’t related/series/sequels? "
Kinda did. Not a challenge, here. Just noting that the post did not follow the premise of the OP.
And where would we be if all posts always strictly followed the premises of the OP’s posts?
Jonah Hill and Seth Rogen
James Franco and Seth Rogen
Chaos. Wrath of God type stuff. Fire and brimstone coming down from the skies! Rivers and seas boiling! Forty years of darkness! Earthquakes, volcanoes… The dead rising from the grave! Human sacrifice, dogs and cats living together… mass hysteria!
For a moment, pretend that I don’t know anything about metallurgy, engineering, or physics, and just tell me what the hell is going on