Agreed
Rainer Werner Fassbinder might have Eastwood beat there. Fassbinder was a very prolific and acclaimed director who released two or more films in thirteen different years by my count, but his most highly ranked ones don’t seem to have fallen in the same year.
Preston Sturges worked very quickly and had two great films in one year several times:
1940: The Great McGinty and Christmas in July
1941: The Lady Eve and Sullivan’s Travels
1944: Hail the Conquering Hero and The Miracle of Morgan’s Creek. He also had The Great Moment that year, but it was shot in 1942 and probably doesn’t fit the criteria of a great film.
Howard Hawks directed both Ball of Fire and Sergeant York in 1941
John Ford:
1935: The Informer and The Whole Town’s Talking (also Steamboat Round the Bend, but that probably isn’t a great film).
1939: Young Mr. Lincoln, Stagecoach and Drums Along the Mohawk
1948: Fort Apache and 3 Godfathers
Alfred Hitchcock
1954: Dial M for Murder and Rear Window
1955: To Catch a Thief and The Trouble with Harry
Buster Keaton:
1924: Sherlock, Jr. and The Navigator.
I love that you included this.
Russ Meyer may not be to everyone’s taste, but he knew what he liked and he made it.
Since quality, full length movies often take a year to produce, two in one year is quite an accomplishment when you think about it.
Akira Kurosawa 1957 - Throne of Blood, and The Lower Depths [which I’ve not seen but won some acting awards, and is in Japanese Top 100 lists]
Joss Whedon, 2012: Much Ado About Nothing & The Avengers.
Neither were nominated nor won any major awards that I could tell, but Werner Herzog did direct two critically-acclaimed films in 1979: Nosferatu the Vampyre and Woyzeck.
Klaus Kinski starred in both. I wonder if production overlapped at all?
Much Ado was not that great, though.
Delete wrong thread
Hitchcock also released The Trouble with Harry and To Catch a Thief in the same year, 1955. I think they both qualify as “great full length movies” .
Spielberg had several years with more than one full-length feature releases that were well-received. Whether they were “great” is subjective
1997 – The Lost World: Jurassic Park and Amistad
2002 – Minority Report and Catch Me If You Can
2005 – War of the Worlds and Munich
I’m not sure either of the entries for 2011 would count – The Adventures of Tintin and War Horse
Akira Kurosawa had four years where he released two full-length feature films, but I think in all those cases only one of the films went on to be considered memorable
I have to disagree with all 3 of your Spielberg additions. The Lost World: Jurassic Park & Minority Report were not great and War of the Worlds was actually a bad movie.
Honda had years in which he directed three, four, or even five feature films, most of which I’ve never heard of. The ones I have are all science fiction or kaiju movies. As Dropo said, for some definitions of great He directed a non-fantastic film, Farewell Rabaul, the same year he directed Gojira. I know nothing about it. Of the years where he directed two that I have seen, I’ll add
1958 – The H-Man and Varan the Unbelievable
1962 – Gorath (Gorasu) and King Kong vs. Godzilla
1963 – Matango and Atragon (I used to have a sports jersey with “Matango” emblazoned on it. I had a fungus infection)
1964 – Godzilla vs. the Thing, Dogora the Space Monster and Ghidrah the Three Headed Monster
1965 – Frankenstein Conquers the World and Invasion of the Astro-Monster
1966 – War of the Gargantuas and Ebirah, Horror of the Deep
1967 – King Kong Escapes and Son of Godzilla
What can I say? I had a misspent youth, watching and re-watching monster movies.
Minoroty Report is a great film and CMIYC is also really good so that is a good shout.
Coulda used a script doctor 
John Huston had several years with two releases, but, again, it’s not clear to me that both were "great’ . One certainly qualifies
1948 – Key Largo and The Treasure of the Sierra Madre
possibly 1972 does – I haven’t seen either film – The Life and Times of Judge Roy Bean and Fat City
I don’t think 1967 counts. The first big-screen version of Casino Royale is a mess ion anybody’s books, even paired with Reflections in a Golden Eye
Ingmar Bergman, 1957: The Seventh Seal and Wild Strawberries
Robert Altman in 1970: MASH and Brewster McCloud
[Apparently he also released two movies in 1979 and two in 1980. Were any great? Popeye was “interesting”)