Here is a list of the approximate dates at which certain popular characters SHOULD lapse into the public domain (barring any further extensions) in the USA. If it were not for the Sony Bono extension on copyright, many of these characters would already be public domain (in fact, in Europe, most of them are). You only have to wait another quarter of a century for them now.
2015 The Little Prince
2020 Gone with the Wind (novel)
2021 Complete Works of Edgar Rice Burroughs (Tarzan, John Carter) and George Orwell (1984, Animal Farm)
2023 Bambi (novel) and The Hardy Boys
2024 Micky Mouse
2025 Buck Rogers in the 25th Century AD
2026 Nancy Drew, Pluto, The Shadow
2027 Babar The Elephant, Winnie the Pooh
2029 Betty Boop, Goofy, King Kong, The Lone Ranger & Tonto, Doc Savage?
2030 Donald Duck, Flash Gordon, Mandrake the Magician, Ming the Merciless, Complete works of Sax Rhomer (Fu Manchu)
2031 Porky Pig, The Little Rascals (Spanky & Alfafa)
2032 Green Hornet & Kato, The Phantom
2033 Daffy Duck, Disney's Snow White, Speed Saunders
2033 Bugs Bunny, The Chronicles of Narnia, The Crimson Avenger, The Tigress, Ultra-Man (Gary Concord), Zatara
2035 Batman, Comissioner Gordon, Cosmo: The Phantom of Disguise, Sandman, The Ultra-Humanite, Chitty-Chitty-Bang-Bang, James Bond, M, Mr. No, Goldfinger, Oddjob, Honey Rider, Moneypenny
2036 The Atom, The Batplane, Black Widow, The Blue Blaze, Cat Woman, Clayface, Comet Pierce, Dr. Fate, Dynaman, Electro, The Falcon, The Ferret, The Firey Mask, The Flash, Flexo the Robot, Hawk Man, Hour-Man, Hugo Strange, Johnny Thunder, The Joker, The Justice Society of America, The Laughing Mask, Marvel Boy, Marvex the Super Robot, Mister E, Red Raven, Robin, Society of Assassins, The Spectre, Thin-Man, Toro, The Vision, The Whip, Wotan, Woody Woodpecker, Complete Works of E.E. Smith (Triplanetary)
2037 Aquaman, Black Marvel, Blazing Skull, Blue Diamond, Captain America & Bucky, Captain Terror, Captain X of the RAF, Challenger, The Destroyer, Dr. Mid-Nite, The Fin, The Green Arrow & Speedy, The Green Lantern, The Hurricane, Jack Frost, Jimmy Olsen, Johnny Quick, Major Liberty, The Mist, Mr. America, The Patriot, The Penguin, Perry White, The Queen Bee, The Red Skull, Rockman, Sargon the Sorceror, The Scarecrow, The Silver Scorpion, Star Man, The Tarantula, The Terror, The Thunderer, The Vigilante, The Whizer, The Witness, Wonder Woman, The Young Allies, Tom & Jerry
2038 Archie & Friends, Blue Blade, Citizen V, Guardian, Little Boy Blue, Rag Doll, Robotman, The Shade, Steve Trevor, Two-Face, Wildcat
2039 Alfred Pennyworth, Brain-Wave, Captain Wonder, Cheetah, Dr. Psycho, Miss America, The Thinker, Toyman, Vandal Savage
2040 Gambler, Giganta, Mad Dog, Mr. Mxyzptlk, Neptune Perkins, Patsy Walker, Psycho Pirate, Solomon Grundy