Samurai Jack is an American animated television series created by animator Genndy Tartakovsky that aired on both Cartoon Network and Toonami from 2001 to 2004. It is noted for its highly detailed, outline-free, masking-based animation, as well as for its cinematic style and pacing. It was the first Cartoon Network original series aside from those who comprised the Cartoon Cartoons lineup at the time. It is shown on its sister network Boomerang.
The plots of individual episodes range from dark and epic to light-hearted and comic, but typically follow "Jack", a time-displaced samurai warrior, in his singular quest to find a method of traveling back in time. Many of the battle scenes in the series are reminiscent of samurai films, and since Jack's robotic enemies "bleed" oil or electricity and monsters and aliens bleed slime or goo, the series is able to exhibit the action of these films while avoiding censorship for violence.
Samurai Jack is no longer available to be viewed by American residents via the Toonami Jetstream website. Production on the show was halted in 2004, but it was never officially ended. In return, Tartakovsky has announced plans to direct a theatrical film, but whether or not it will resolve the series has yet to be announced.
Source: Wikipedia, "Samurai Jack", available under the CC-BY-SA License.