If you loved Code Geass: Lelouch of the Re;surrection, try Code Geass: Lelouch of the Rebellion II - Transgression
A bridge between a film you've already seen and one most people haven't. Code Geass: Lelouch of the Rebellion II - Transgression has roughly 3.8× fewer votes than Code Geass: Lelouch of the Re;surrection — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Code Geass: Lelouch of the Re;surrection

Code Geass: Lelouch of the Rebellion II - Transgression
What they share
Both films are directed by Goro Taniguchi, and they both carry the cerebral mood tag, and they sit in Animation / Science Fiction territory. If that's the register that drew you to Code Geass: Lelouch of the Re;surrection, the second film will land in a comparable space — through a different lens.
What Code Geass: Lelouch of the Rebellion II - Transgression is
You command the Black Knights against Britannia. Victory follows victory. But Suzaku and a strange child arrive, threatening all you've built. Taniguchi's pacing splits his fanbase; some appreciate the focus, others miss the original's broader scope.