It depends on what you like. Flannery O'Connor's fiction is extraordinary. I bet you'd like Nabokov based on what you've said so far; I like his earlier Russian novels best (which have excellent English translations), like The Defense, for example. If you want to go whole hog into postmodernism then try Pynchon or Gaddis.

The 19th century Russians from Gogol to Chekhov are pretty much can't-lose. Turgenev's Fathers and Sons is beautiful and captures the spirit of youth.

Ford Madox Ford's The Good Soldier is a short masterpiece. The Great Gatsby is as good as its reputation says. Read Dickens if you want the essence of the English language and character. Read Kafka for the strangest articulation of modernity. Bruno Schulz is more whimsical. Borges is another whom your list suggests you should try.

If you really want to go down a rabbit hole, find Martin Seymour-Smith's Guide to Modern World Literature and browse through it to blow your mind. It covers everything and seems impossible, except it exists so it can't be.