This is a great Teen Titans poster by George Perez!
Let’s see if I can name them all: Raven, Starfire, Terra, Cyborg, Kid Flash, Wonder Girl (Donna Troy), Robin (Dick Grayson), and Changeling. Those are the main ones, and then I can see: Speedy (Roy Harper), Lilith, Pre-Crisis Hippolyta, Terry Long, Arella, Red Star, Thunder and Lightning, and Magenta (?).
The villains are: Trigon, Brother Blood, Blackfire, and Deathstroke.