With this decade I'm taking a bit of a different approach, because I was only really able to come up with about 30 great films, in my estimation, from the 1920s, with as few as two from some years. So I was able to simply rank those, giving me the following list:
1 Metropolis (1927)
2 Sunrise (1927)
3 The Gold Rush (1925)
4 Safety Last! (1923)
5 The Big Parade (1925)
6 The Kid (1921)
7 The Jazz Singer (1927)
8 The General (1926)
9 Dr. Mabuse the Gambler (1922)
10 The Cabinet of Dr. Caligari (1920)
11 Wings (1927)
12 Battleship Potemkin (1925)
13 The Lodger (1927)
14 The Cocoanuts (1929)
15 Nosferatu (1922)
16 The Last Laugh (1924)
17 The Passion of Joan of Arc (1928)
18 Lonesome (1928)
19 Steamboat Bill, Jr. (1928)
20 Blackmail (1929)
21 Spies (1928)
22 The Adventures of Prince Achmed (1926)
23 Diary of a Lost Girl (1929)
24 Pandora's Box (1929)
25 The Man Who Laughs (1928)
26 The Phantom Carriage (1921)
27 Faust (1927)
28 Greed (1924)
29 The Hunchback of Notre Dame (1923)
30 The Golem (1920)