I recently wrote this comment on another thread. I'll repost it here, you should mine that thread for things too.
https://hexbear.net/comment/5648363
Trigger's shows:
Gurren Lagann is about a double revolution.
Kill la Kill is about a revolution, social norms, and different methods of praxis.
Little Witch Academia has extremely strong class themes.
Promare is about a failed global revolution, followed by the defeat of a fascist.
Miyazaki/Studio Ghibli, he's a communist or at least was. He still holds all the same views he had before the fall of the USSR. Everything he makes is marxist in some way whether he still calls himself one or not.
Akira is set upon the backdrop of an obviously marxist revolution.
Shinsekai Yori has deeply political themes but they don't really start until parts 2 and 3. Any leftist will sympathise with Squealer.
One Piece - This is explicitly a marxist story that is building up towards world revolution. The author Oda has Che Guevara on the wall of his office.
Gundam are not explicitly marxist but political themes lean into marxism at times. Some shows better than others, I'm not a gundam expert.
Revolutionary Girl Utena - about breaking gender standards in society. Queer show.
Madoka Magica - I argue this show is explicitly marxist and the entire relationship between magical girls and the system is explicitly a critique and call for revolution over capitalism.
Deca-Dence - Explicitly marxist show. The ending is cowardly though.
Sarazanmai is Kunihiko Ikuhara's most direct attack on capitalism
Kino no Tabi: The Beautiful World - Start with the 2003 version not the remake. Each episode is kinda independent and explores philosophical themes.
Houseki no Kuni (Land of the Lustrous) - What is depicted is an explicitly a communist society with a communist economy. Show features incredible art, incredible directing, and incredible use of body horror to depict the inner feelings of characters. In terms of modern anime it has done more than anything in the genre to change the way the rest of the industry works by demonstrating what 3d used correctly can do for the genre. This show is a masterpiece and one of my favourites, rewatching it always brings new things to analyse or think about.