What is a good Аниме series for someone who likes code geass and nabari no ou .

I'll recommend: Death Note because if Ты like Code Geass you'll Любовь that. I'll also recommend FMA

Rurouni Kenshin

Fullmetal Alchemist, Loveless (If Ты don't mind slight yaoi), 07 Ghost, maybe Ghost Hunt, and that's all I can think of right now...
Those animes have the genre military, supernatural, action, или all of them.

Those are 2 of my fav's as well so u may also like:
Энджел Beats
Blue Exorcist (Ao no Exorcist)
07 Ghost
Another
Durarara!!
Darker Than Black
Trinity Blood
Fullmetal Alchemist Brotherhood
Death Note

I think of Death Note when Аниме similar to Code Geass is mentioned (though I personally prefer Code Geass). I also recommend Gurren Lagann and Evangelion if Ты enjoyed the mech aspect of it.

I think a person who enjoyed Nabari no Ou would also like Pandora Hearts, Loveless, and maybe Soul Eater...?