It was 'Invincible' for me.
And Pilot Pirx stories - the atmosphere that flying spaceships is just dirty, demanding, lonely job like driving a lorry. 1978 Polish-Soviet film based on 'Pilot Pirx Test' was very good ...
And Futurological Congress.
EDIT: Also Perfect Void (Doskonała Próżnia) and Imaginary Value (Wielkość Urojona) - introductions to non-existing books and Inquiry (Śledztwo) - one of two Lem's quirky crime novels about mysterily disapearing corpses from mortuaries...
https://pl.m.wikipedia.org/wiki/Lista_pierwszych_wyda%C5%84_...