Code Geass: Lelouch of the Rebellion - Recommendations

Alt title: Code Geass: Hangyaku no Lelouch

If you're looking for manga similar to Code Geass: Lelouch of the Rebellion, you might like these titles.

Aldnoah.Zero

Aldnoah.Zero

Years after a great war was waged between the portion of humanity that migrated to Mars and those who chose to remain on Earth, a tentative peace has been struck. But not everyone is happy with the status quo. When the Princess Asseylum of Mars makes a diplomatic visit to Earth in an effort to strengthen ties, some see it as an opportunity to reignite the flames of war. Can the citizens of Earth stand against the awesome might of the Martian Kataphrakts a second time?

I agree

Gunslinger Girl

Gunslinger Girl

The Social Welfare Agency, acting under the cover of a charitable organization that aids the physically injured, is actually a military organization specializing in anti-terrorism. One of its branches, Section 2 of Special Ops, uses mechanically-enhanced young girls as assassins. They each have their individual 'handler', who is free to use whatever methods they like to train them. Henrietta is one of these cyborgs. But despite being subjected to a brainwashing process called 'conditioning', and being trained to fight and to kill, she still has the heart and emotions of a young girl.

I agree

Dimension W

Dimension W

AD 2072. With the invention of cross-dimensional electromagnetic inductors known as Coils, the world’s energy crisis has long been solved. Kyouma Mabuchi is a “Collector,” someone who makes his living by recovering illegal Coils for the powers that be. When on his latest gig he crosses paths with a mysterious girl named Mira, little does he know that their meeting will bring them both closer to the secrets behind “Dimension W,” the fourth dimension–beyond X, Y, and Z–that powers the world…

I agree

Deadman Wonderland

Deadman Wonderland

Middle school student Ganta Igarashi witnessed the slaughter of his entire class by the mysterious 'Red Man', and as the only survivor, he was labeled a mass murderer and sentenced to death. Now an inmate at the privately-owned prison and ‘amusement park' known as Deadman Wonderland, Ganta must try to survive in a place where inmates are the main attraction in brutal gladiator-style games. At the same time, he must attempt to uncover the truth behind the ‘Red Man', his mysterious childhood friend Shiro, and why he was the only survivor that bloody day.

I agree

King's Maker

King's Maker

Wolfgang Goldenleonard, the 4th Prince of the kingdom, returns to the palace after years of living in hiding. He rejects everything about his new royal life, but is intrigued by the mysterious and dutiful Shin Soohyuk, a catamite of the King. As Wolfgang slowly opens up and learns the ways of the palace, Soohyuk begins to see something special about the wild, unkempt, and stubborn young prince. He might just be the one Soohyuk has been waiting for... the one who could light the flame of rebellion.

I agree

Elfen Lied

Elfen Lied

In the near future, some girls are born mutated. Known as Diclonius, this new species is believed to have been chosen by God to wipe out mankind. Unlike regular humans, Diclonius have two horns on their head and ‘vectors' - invisible ‘hands.' Contained within a research facility unknown to the world, the Diclonius are experimented upon mercilessly; many die or develop a hate for mankind. One such creature, Lucy, is said to be the first of the Diclonius. She escapes from the facility, but while fleeing she takes a bullet to the head and is seemingly killed. However, it seems Lucy isn't quite dead yet; she's instead developed an alternate personality called Nyuu. She's washed up on a shore where two people, Kouta and Yuka, find her and bring her home, unaware that such a monster still lurks within Nyuu. 

I agree

Quickly Wear the Face of the Devil (Novel)

Quickly Wear the Face of the Devil (Novel)

A top hacker was chosen by the Lord God to be reborn into countless worlds, always as an expendable villain. With no free will, every world became a dead end. Every one of his lives ended tragically. Finally, after wresting control of the Villain System, this ace hacker decided to enact revenge. Even if his very bones were rotten, he’d choose to occupy the very heights of morality, if only on the surface. Thus, he would change his fate as an abused slag.

I agree