The closing credits for the 1956 movie Around the World in Eighty Days definitely deserves mention – they’re the longest closing credits I know of in a film of that vintage. It’s made up of animation and graphics by the legendary Saul Bass, and it essentially retells the entire story in miniature so that you know who is being referred to in the credits (rather than the uninformative “Sailor #1”, for instance). And the whole thing was done in Todd-AO widescreen (so what you see here is an approximation)
MASH is another example.
Two more sets of closing credits aren’t as elaborate as those of Around the World, but deserve attention.
For A Funny Thing Happened on the Way to the Forum they used animated credits done in the style of Roman wall paintings and mosaics. The flies are supposed by some to be a reference to the constant flies they had around the set during production
The closing credits to West Side Story were done in the style of graffiti and street art
That’s not the only thing going on on the Marauders’ Map, either.
The end credits for the documentary Sunset Strip (2012) accompany an animated take on the history, architecture and personalities of the area throughout its history.
In Michael Clayton (2007), the entire end credits roll while George Clooney sits in the back of a cab not showing any semblance of the triumph he has just achieved…until he cracks a smile at the very end.
In City of Women (1980) directed by Fellini, as Marcello Mastroianni’s name comes up in the opening credits, an offscreen voice says “With Marcello again?”
In The Wild Bunch (1969), director Sam Peckinpah’s credit comes onscreen just after William Holden announces: “If they move, kill 'em.”
The 1940 film Fantasia originally had no opening title. The title card was used at intermission. I don’t think there were originally any end credits.
On subsequent releases, the title card showed up at the beginning, instead (the first time I saw the film with the title card properly placed was on its first DVD release). They eventually added end credits to properly credit the animators involved.
I hope this doesn’t take this too far from the OP’s intent, but, having mentioned Saul Bass’ credit for Around the World, I also have to mention Maurice Binder. Although he’s probably best known for the titles he did for the opening of most of the James Bond movies from 1962 through 1989 (as well as for a few other films, such as Arabesque, and a non-title sequence for the 1979 Dracula), I really like his very different animated opening credits for Stanley Donen’s Charade
It’s not earlier, but in the Ghibli movie “Only Yesterday” (1991), when the movie seems to be over and the closing credits start playing…the animation continues, and the entire (wordless) resolution of the movie occurs behind the credits.
If you squint just right, THIS IS SPINAL TAP.
The 2011 prequel to The Thing’s ending credits mesh up almost exactly with the 1982 movie’s opening credits. I thought was pretty awesome, even of the movie itself was only decent at best…maybe decent+…compared to carpenter’s masterpiece.
The Count counts the credits at the end of Sesame Street Presents: Follow that Bird.
“One Joan Ganz Cooney! Hi, Mom.”
And then he counts the rest at the very end.
In The Odd Couple Oscar kept mixing up the names of two of the girls. In the closing credits they initially switch the names of the two actresses that played the girls. Then they corrected it.
The Lego Movie 2: The Second Part end credits has The Lonely Island singing about how cool and awesome the credits are:
Somewhat similar – in the end credits for Disney’s Mary Poppins the credit for Mr. Dawes, Senior is given as NAVCKID KEYD . The letters are animated and re-arrange themselves to de-anagram as “Dick Van Dyke”, who played the part in heavy makeup.