If you were gripped by Gilbert Gosseyn's relentless pursuit of truth and identity in The World of Null-A, you'll find The Demolished Man equally thrilling. Bester's protagonist, Lincoln Powell, is locked in a cat-and-mouse pursuit with a murderer in a world where telepathy upends the rules of crime and justice. The novel's propulsive plot and high-stakes objectives will keep you hooked from start to finish.

If the philosophical puzzles and questions about identity, logic, and reality in The World of Null-A fascinated you, Use of Weapons will challenge you further. Banks weaves a complex narrative around Cheradenine Zakalwe, whose personal struggles and moral ambiguities are deeply tied to meditations on violence, memory, and the nature of self. Prepare for a thought-provoking experience.

If you were drawn into van Vogt's elaborately constructed Null-A society and its unique institutions, City will delight you with its far-reaching worldbuilding. Simak's interconnected stories paint a sweeping vision of a future Earth, exploring the evolution of dogs, robots, and humanity through myth and legend. The setting is both imaginative and richly detailed.

If you were fascinated by the encounters with non-human intelligence and the conceptual puzzles in The World of Null-A, Solaris will captivate you. Lem’s story centers on the mysterious, sentient ocean of the planet Solaris, whose incomprehensible actions force the human characters to confront the limits of understanding and communication with the truly alien.

If you enjoyed the reality-warping twists and mental games that Gilbert Gosseyn faces, Ubik is a must-read. Dick’s protagonist, Joe Chip, is caught in a shifting world where the line between life and death blurs, and reality itself is constantly undermined by strange events and revelations. Expect surprises at every turn.