I have this rule: The quality of an anime is inverse of the number of episodes it has.

Of course it is not always true but It is a good rule of thumb. Without knowing what you like, read some sinopses of the classics and see if any sparkle your interest.

You are already in a good track with movies, you can watch Akira or the first Ghost in the Shell for some good action sci-fi.

I personally didn't watch yet, so is not quite a recommendation but any Satoshi Kon movie is always very well received, like Perfect Blue.

There is some anthology movies, each with 3-4 short stories, that seems to be quite Good. I watched and liked alot Memories, and heard about Neo Tokio and Robot Carnival. All of them have one section done by Katsuhiro Ótimo, the author of Akira.

You can look up some OVA that are 1 to 6 EPS long like Read or Die, Bastard (the original one) and Blood: The last Vampire (the original one)

Some TV series that are 13 to 26 episodes long I really liked is Samurai Champloo. I also like the Netflix's Castlevania (the first one) and I cannot vouch for it because I didn't finish yet but Cyberpunk: Edgerunners was pretty good.

The next two are quite controversial but I think quite good are Kite and Mezzo Forte, both are 1 or 2 ep OVA. They are controversial because they are a mix of action anime and some hardcore hentai, but there are some cuts without the sex stuff (that is also completely unnecessary if I remember correctly). The action scenes are really good.