For me, One Flew Over the Cuckoo's Nest.

Every subsequent watch, I add more to the commentary of "Is he crazy?" and "Is Nurse Ratched evil or just doing her job?"

Tenet. I’ve watched it probably four times. Got my sister onto it and I think she’s seen it like seven times now.

Very rewatchable. It can make sense but I’d say it takes you at least two viewings to follow along. Probably three.

I wish there was a sequel but I don’t think that’s Christopher Nolan’s style.

I see other Nolan movies listed here. There’s definitely a theme in them with time, story order and apparently, dead wives?

The Holy Mountain. I suggest just watching it.

Tenet, watched it thrice to get the jist of it.

Until EEAAO came.

Tenet had that rollercoaster feel, which was surprisingly good. EEAAO was gentle, slowly elevating to the "showdown".

The parallel universes and alternate lives? by far the coolest.

Would serial Experiments Lain count? Anime series that seems to change after each rewatch.

Clerks, there are so many great gems buried in that movie.

Deja Vu with Denzel Washington and Jim Cavisal or however you spell it. Terrorist murder mystery with a bit of a look into the past.

Enter the Void (2009). Super trippy and one of those movies that leaves you wondering about everything each time you watch it.

Titanic. The ending recontextualises everything and I'm still talking about it

Primer because you don't know what's happening at the start, and then you start to piece it together, but you really have to watch it a few times because the details you pick up provide context for what's happening allowing you to piece more of the puzzle together.

Not a movie, but bojack horse man. On the first watch it all just seems like shitty bojack. After learning all the back story its more like, oh poor bojack.