If you liked the ES: Eternal Sabbath manga, the Anime-Planet community thinks you'd like:
In 2010, the Britannian Empire enslaved Japan after a brutal month-long assault; in the aftermath Japan was renamed Area 11, and its people began a hard and terrible existence. Lelouch, a Britannian student living in Area 11, has grown up hating the Empire and everything it stands for. One day, while investigating a crashed military plane, Lelouch meets a mysterious girl who grants him the ability to control minds. Can he use his new power to fight for freedom, or will his hatred twist his good intentions into mindless acts of vengeance?
Both main characters have powers whick allow them to control other people's acts and choices, and both are bored with their lives. Although the story development is very different, this same plot is enough to make ES a good recommendation for Code Geass fans and vice versa.
Power corrupts, and absolute power corrupts absolutely. Top-ranked student Yagami Light is disenchanted with the world around him. Through a series of events, he comes into possession of the ultimate power over life and death: a supernatural "death note" which can kill nearly anyone at his whim. As Light sets off on a crusade-turned-killing-spree, investigators from a police task force try to stop the mysterious deaths - including Light's own father, a senior policeman.
Both anime circle around a main character bored with his life and the person trying to figure out the powers of the main character (though the latter is a bit different in each manga). The art style in both is highly realistic and detailed.