When the S-Team was founded, it was with the following roster: Sandstorm, Science Guy, Stonewall, Shellshock, Smokescreen, Stretch, Slick, and Silence. The original Justice League roster was: Superman, Batman, Wonder Woman, Green Lantern, The Flash, Aquaman, and the Martian Manhunter (going by the original Silver Age lineup, not counting any revisionist continuity)–most of whom will be known even by casual non-fanboys.
Sandstorm, Science Guy, Stonewall, and Silence have all left the team for personal reasons, and Shellshock is dead. Replacement characters include the Scarlet Swordsmistress, Stallion, and three members of the erstwhile Legion of T, renamed from Turbo to Supercharger, Tortoise to Shield, and TigerGirl (who kept her name). The current Justice League roster as of May 2011 is (to my best knowledge): Donna Troy, Cyborg, The Atom, Batman (Dick Grayson), Doctor Light, Congorilla, Jade, Jesse Quick, Starman (whichever version THIS one is), and Saint Walker. If you’re going “Who?!” then you understand why the Justice League title has worked its way down to the bottom of my reading stack, and I’m a longtime DC fan.
