Code Geass: Fukkatsu no Lelouch

It is similar because the main character is smart and wants peace, but there are differences among them the Light Yagami the main character of death note wants to kill anyone in his way to conquer the world while Lelouch the main character of Code Geass wants to defeat the Britannians.  

With the world unified at last, a new conflict emerges. In Lelouch of the Re;surrection, a nation that Britannia once couldn't conquer has kidnapped Nunnally. In A Wakening of the Trailblazer, an extraterrestrial threat emerges, and humanity is tested as to whether they are unified enough to initiate first contact. Both feature former enemies which extraordinary ace pilots now fighting alongside each other with a common goal, expect a lot of familiar faces. Lingering plot threads are resolved and they both end on a happily with similar messages about peace. 

The world is at peace at the end of these two works' respective prequels but there is still lingering conflict. In Lelouch of the Re;surrection, there are gates untouched by Charles and remnants from the Geass Order using their abilities to cause conflict. The antagonist, Shamna, may possibly finish what Charles started. Whereas in Endless Waltz, the heir to the defeated antagonist Treize Khushrenada, Mariemeia, resurrects the original plan for Operation Meteor, threatening to drop colonies on to Earth. Both of these movies from Sunrise discuss a world of peace, and if it is a true peace when there are soldiers left without purpose (followers of Mariemeia like Chang in Endless Waltz, and the Kingdom of Zhilkstan in Lelouch of the Re;surrection, whose largest export is warriors). read more 

Elisa Magic Ability = Shamna Geass, it's a similiar things that you can bring memories back to the past 

Both have a return to time story.  

While Code Geass has more intrigue and Gurren Lagann has more humor, both showes have spirit and sacrifice. The weak rebelling againt the strong in giant robot battles! As well as similar endgame themes. 

Both are great mecha anime with great plot and history 

These 2 films are sequels to their respective TV series that have ended long ago and takes place with the united world fighting against the emerging kingdom whose history has relevance to the previous antagonists led by a blond female.  

CC and Akemi due to their obsession and personal reasons are in a desperate journey to save the protagonists after unsuccessful attempts involving an antagonist whose goal is to do whatever it takes to save that is deemed necessary to them for the good. Unlike the main series, it revolves around the deutaroganists of the story as protagonists in their own narrative and devleopment. The movies take place after the recap movie trilogy and this sets off a new journey as an alternate universe diverting from the main trilogy. 

Both involve an antagonist that can do mental time travel and anticipate the hero's actions when they rewind time. The protagonists must use their own abilities to figure out and counter the antagonist's abilities. This is more fleshed out in Diamond is Unbreakable due to it being a television series. 

Similar to how CCA takes place after movies, FnL takes place after the main story (movies, not the show) and deals with antagonists from their respective nations that are said to be powerful with ambitious intentions to change the world and society for better that pits the protagonists once again to stop them. 

Both popular stories feature an alternate change of time to feature a plot retaining the same casts revolving around the antagonists with similar elements putting the world at risk once more with different character personalities and plot developments that put's one shoes to the whole new level that allow nostalgia to flourish through our minds as we all grew up with watching the hit series to begin with  

Both are alternate take on their series as films meant to reconstruct the tropes deconstructed in the previous series focusing on other characters aside from the main protagonist who took up a lot in the main series. Fukkatsu No Lelouch leaves a new branch for more series to pave way while 3.0 + 1.0 ends on a note that all Evangelion fans desired for years since EoE. 

Post story arcs revolving around the casts who live after the fate of the protagonists who brought world to peace but this time focus on another character as a protagonist (C.C. and Kaiba) who attempts to bring them back to satisfy their personal desires but at the same time dealing with the new threat who once again bring the world under their heels by threatening their friends.