O'Neill cylinders are also frequently depicted in the various Gundam series.
https://colonydrop.podbean.com/e/space-colonies/
For actual in-depth scientific exploration of the colonies of Gundam, Dyar Straights is pretty great:
In fact, starting with 0080 war in the pocket isn't a bad idea given the self contained story.
From there, I'd check out 0083: Stardust memory and move on to the Zeta Gundam tv show.
Then, for a completely different experience, you can check out the alternate universe shows like Mobile Fighter G Gundam or After War Report Gundam X