According to Duke University, these are a sample of books and plays that entered US public domain January 1st 2024. They also list some films and audio recordings too.
D.H Lawrence, Lady Chatterley's Lover
Bertolt Brecht, The Threepenny Opera (in the original German, Die Dreigroschenoper)
Virginia Woolf, Orlando
Erich Maria Remarque, All Quiet on the Western Front (in the original German, Im Westen nichts Neues)
W.E.B. Du Bois, Dark Princess
Claude McKay, Home to Harlem
A. A. Milne, illustrations by E. H. Shepard, House at Pooh Corner (introducing the Tigger character)
J. M. Barrie, Peter Pan; or the Boy Who Wouldn't Grow Up (because the play’s script was not “published” for copyright purposes until 1928; note that Barrie’s 1911 novel “Peter and Wendy” has been public domain since 1967)
Radclyffe Hall, The Well of Loneliness
Evelyn Waugh,Decline and Fall
Agatha Christie, The Mystery of the Blue Train
Wanda Gág, Millions of Cats (the oldest American picture book still in print)
Robert Frost, West-Running Brook
Ben Hecht and Charles MacArthur, The Front Page
https://web.law.duke.edu/cspd/publicdomainday/2024/