[Wiosna]

Some recommendations that I think you'd like, from highest priority to lowest:
- Stalker (Andrei Tarkovsky)
- It's Such A Beautiful Day (Don Hertzfeldt)
- Koyaanisqatsi (Godfrey Reggio)
- Eureka (Shinji Aoyama)
- All About Lily Chou-Chou (Shunji Iwai)

Stalker seems like the most obvious recommendation given your thoughts on Solaris. I like Solaris a bit more than Stalker (8/10 vs. 7/10), but I enjoyed both films. I'd also suggest The Handmaiden (Park Chan-Wook) for a similar reason, but Oldboy was a much more visceral watch in comparison to Handmaiden for me... but you might find more merits in Handmaiden than I would, I feel like.

I find it hard-pressed to recommend anime films to you because you don't seem to be the type to enjoy in-your-face drama/melodrama, and a lot of my favourite anime movies tend to be quite saccharine. I do feel that a lot of canonical anime movies focus more on (melo)drama, and as a result I don't think a lot of Japanese animation for you. There are many clear seminal exceptions to this (mostly sci-fi ones like Akira or End of Evangelion), but most contemporary anime films that are received well tug more on the heart in explicit ways. I wouldn't recommend any of them (including Your Name and Weathering With You, even if the films came from my favourite director).

If you're looking for animation in particular, I feel that Howl's Moving Castle (Hayao Miyazaki) and Perfect Blue (Satoshi Kon) are best up your alley, though I wouldn't consider Perfect Blue my favourite film from Kon (Millennium Actress resonates more with me). Howl's Moving Castle in general feels like one of Miyazaki's most ambitious but also laser-focused given the motivations behind making the film, and I feel that Howl's Moving Castle also really shows what Miyazaki is like both as a director and person. I think Jin-Rou: The Wolf Brigade (Hiroyuki Okiura) is also a good shout.