If you loved The Disappearance of Haruhi Suzumiya, try Love, Chunibyo & Other Delusions! Rikka Version
A bridge between a film you've already seen and one most people haven't. Love, Chunibyo & Other Delusions! Rikka Version has roughly 3.1× fewer votes than The Disappearance of Haruhi Suzumiya — 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.

The Disappearance of Haruhi Suzumiya

Love, Chunibyo & Other Delusions! Rikka Version
What they share
Both films are directed by Tatsuya Ishihara, and they both carry the bittersweet mood tag, and they sit in Animation / Comedy / Drama territory. If that's the register that drew you to The Disappearance of Haruhi Suzumiya, the second film will land in a comparable space — through a different lens.
What Love, Chunibyo & Other Delusions! Rikka Version is
Apparently romance can be found in delusions. Rikka's perspective retells the first season with new elements. It somehow ties everything together.