If you loved Lupin the Third: Jigen's Gravestone, try LUPIN THE IIIRD: The Movie - The Immortal Bloodline
A bridge between a film you've already seen and one most people haven't. LUPIN THE IIIRD: The Movie - The Immortal Bloodline has roughly 5.1× fewer votes than Lupin the Third: Jigen's Gravestone — 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.

Lupin the Third: Jigen's Gravestone

LUPIN THE IIIRD: The Movie - The Immortal Bloodline
What they share
Both films are directed by Takeshi Koike, and they both carry the foreign gem mood tag, and they sit in Action / Animation / Crime territory. If that's the register that drew you to Lupin the Third: Jigen's Gravestone, the second film will land in a comparable space — through a different lens.
What LUPIN THE IIIRD: The Movie - The Immortal Bloodline is
You infiltrate a mysterious island with Lupin III, but then a monstrous enemy emerges, threatening his legacy. The director's dark animation style sets the tone.