Collected Fictions is every short story Borges wrote, in one book. I came across it in a review of Invisible Cities, a book I loved. The reviewer says his first review on the channel was of Borges, and that it should be your desert island book:
If you just have one desert island book, one book for the rest of your life, that’s the one.
Catherine K. also mentions Borges alongside Clarice Lispector in this video as two writers whose work feels like dreams.