3. The Justice Society of America
The Justice Society of America was created in 1940 as a way for DC Comics to feature their lesser-known heroes, who had not yet starred in books of their own. Popular members of the team include Hawkman, Dr. Fate, The Atom, Stargirl, The Spectre, Dr Mid-Nite, Tomcat, Green Lantern (the Alan Scott incarnation) and The Flash (the Jay Garrick version). The JSA has often been portrayed as a precursor to the Justice League, often taking place in the past or in some cases, in an alternate timeline. The roster and role that the JSA has had has changed over the years, and often gets help from members of the Justice League. A JSA film could open the door for DC's characters that are unknown to general audiences, and could act as a superhero period piece, existing in the same cinematic universe as their more mainstream characters. Each member is also distinctly different than those in the JLA, which would add a bit of variety to the DCU (while also leaving the possibility for crossovers and cameos).