Some of these have already been mentioned but I would suggest the following:
What Is To Be Done by Chernyshevsky. Lenin read it five times in a summer and named his pamphlet after that. Xi Jinping lists it as a fave too. It was huge in the years leading up to the October Revolution. It has better credentials as revolutionary socialist literature than probably anything else. It is a cozy read, and i think the narrator is funny.
The Dispossessed by Le Guin. Yeah it is anarchist, but i think it's interesting how she explores both liberalism and anarchism, and imagines how things like language change when your mode of production do. I have a twitter thread on some highlights/questions it explores (spoilers though).
Babel by RF Kuang. This is not socialist, IMO, and its anti-capitalism is more anti-imperialism rather than taking the form of moving past capitalism. Still it's a fun read; the world building replaces mechanization with magic, and explores how industrialization/capitalism leads to imperialism (eg Opium Wars). I have a thread on some of the world-building in it and why it's neat from a socialist angle here (again, some spoilers).
I did read The Jungle too, but i thought it was kinda dated, miserable and uninspiring. Maybe you like it better than I did.