No translation is perfect. Every language (at least according to some anthropologists) has its own point of view or way of looking at the world. This is one of the main reasons why, whenever possible, many people try to read literary works in their original language: it's the best way of experiencing the author's original intent. Your average translator may know two languages very well, but they may lack sensitivity, resourcefulness, or just the "poetic talent" needed to make a perfect translation. Something gets lost along the way.
But there is another possibility: that the translator is an author in their own right. There's no better translator for a literary work than another literary author, who has both the knowledge and the writerly skill.
A Golden Translator is a prestigious or canonical writer in the same genre (or sometimes another genre) that translates works into their native language, perhaps even uplifting the value of the translated work to the new audience. They may introduce little variations in order to maintain or even "improve" the spirit of the original work.
- Kalpa Imperial from Angélica Gorodischer was translated to English by Ursula K. Le Guin.
- Jorge Luis Borges translated to Spanish works from Edgar Allan Poe, Franz Kafka, James Joyce, Hermann Hesse, Rudyard Kipling, Herman Melville, Andre Gide, William Faulkner, Walt Whitman, Virginia Woolf, Henri Michaux, Jack London, Gustav Meyrink, Novalis, Marcel Schwob, George Bernard Shaw, May Sinclair, Jonathan Swift, H. G. Wells and G. K. Chesterton, introducing subtle variations in order to "improve" the works.
- The Argentinian author Julio Cortázar translated the entire works of Edgar Allan Poe, Memories of Adriano from Marguerite Yourcenar, Robinson Crusoe, from Daniel Defoe, and Life and Letters of John Keats, from Lord Houghton.
- The awarded Argentinian science fiction writer Carlos Gardini has translated many science fiction works from English (including among others works from Cordwainer Smith) mainly for the magazine El Péndulo, but also several novels for Minotauro Press.
- Charles Baudelaire translated Edgar Allan Poe to French.
- Mauro Mantella, a comic book writer, is the Argentinian translator of The Walking Dead.
- Santiago Garcia, a Spanish comic book author and scholar, translated several comic books to English.
- Cesar Aira, one of the best contemporary Argentinian authors, has translated Maus for Argentina too, even making his way to the Education Ministry press for schools and university libraries.
- The musical Man of La Mancha was translated into French by famous songwriter Jacques Brel, who also played the lead in the original French production.
- French playwright Yasmina Reza has had her main plays (Art, Life x3, and God of Carnage) translated by notable English playwright Christopher Hampton.
- A backward example - Russian playwright Anton Chekhov's major plays were all translated to English in the 1900s by Constance Garnett, but those translations are considered stodgy and many modern playwrights have translated or adapted his work, including David Mamet, Neil Simon, and Lanford Wilson.
- The contemporary poet Anne Carson is also a classical scholar who has produced well-regarded translations of Sappho and the Greek tragedians.
- Adam Mickiewicz, considered one of the greatest (if not the greatest) Polish poets, translated Byron's The Giaour.
- Samuil Marshak is one of the best known Soviet writers for children. As for the translations... when he died, a heather wreath was sent to his funeral from Scotland, for his translation of Robert Louis Stevenson's Heather Ale (which notably has a page on the Russian Wikipedia, but not the English one).
- H.R.Haggard's King Solomon's Mines was translated into Portuguese by the acclaimed Eça de Queiroz.
- Machado de Assis, perhaps the most revered Brazilian writer of all time, translated Charles Dickens' Oliver Twist and Victor Hugo's Les Travailleurs de la Mer to Portuguese.