Season one is about Robin fighting Slade. Season two is about the team fighting Terra and Slade. Season three is about Cyborg fighting Brother Blood. Season four is about Raven fighting Trigon. Season five is about Beast Boy fighting the Brotherhood of Evil. Starfire is the only one of the main characters to not have a season generally focusing on her.
The word "kill" is never used in this series, although it is often implied, using words like "destroy" or "annihilate"
The opening credits of the show featured two versions of the theme song: one in English and the other in Japanese. The Japanese version is not a direct translation of the English lyrics. Beast Boy sings a translation of the Japanese Lyrics in Teen Titans: Trouble in Tokyo (2006).
Slade Wilson (A.K.A. Deathstroke The Terminator) is significantly different from his comic book counterpart. The animated version was changed a bit to a more traditional criminal mastermind. In the comics, Slade was a high priced bounty hunter in the mold of Boba Fett. In addition, the name Deathstroke was considered too violent-sounding, so the producers decided to stick with his real name. Slade's uniform changed to be black and silver instead of the blue and orange uniform from the comics, however he retains the orange on the eye slit side of his mask.
In the DC Comics, Raven is not a telekinetic. Thanks to the popularity of the show and her character, her comic counterpart was brought back from the dead.