If you enjoyed Journey to the West, I'd also expect it to recommend Water Margin (a.k.a. Outlaws of the Marsh), Three Kingdoms (a.k.a. Romance of the Three Kingdoms), The Tower of Myriad Mirrors (a.k.a. A Supplement to Journey to the West), Quelling the Demons' Revolt (a.k.a. The Three Sui Quash the Demons' Revolt, a.k.a. The Sorcerer's Revolt), or (if you enjoy short stories), Strange Tales from a Chinese Studio.

For each of these, I've generally linked to the translation that I understand to be best, though I'm not an expert. But regarding Quelling the Demons' Revolt, I've linked to an upcoming translation by someone well-known for their translations of 17th C. Chinese literature. Its previous translations are very different, because they're based on different texts--a shorter "original" and a later version doubled in length by a similarly famous writer--and I'm not sure which of those the new translation will be based on.

Anyway, Dream of the Red Chamber is one of the Four Great Classical Novels along with several of those listed here, but if you enjoyed the wild adventure elements of Journey to the West, I think you'd want to know about these others too. On the other hand, if Dream of the Red Chamber's plot appeals to you, then you should know about The Plum in the Golden Vase--I'm nearing the end of volume four (out of five) at the moment, and it has been an amazing read.