Alright, for my third pick, in the World Literature category, I pick The Collected Fictions of
Jorge Luis Borges.
This particular book from Penguin has every story that Borges ever wrote. All of them. I've seen some reviews knock the translation in this particular edition but frankly I don't speak Spanish and would have no idea if I was reading a good or bad translation. I do know that having all the stories from one of my favorite writers together in one big book is really handy. The chronological presentation lets you really get the feel for how this man redeveloped the entire idea of what a short story is and what it can accomplish. By the time you get into the middle - Ficciones and The Aleph - you're really reading stories unlike anything you've ever encountered.
Anyone who likes mysteries, Vikings, HP Lovecraft, mazes, puzzles, Phillip K Dick, Salman Rushdie, Neil Gaiman, the Arabian Nights, or just great short stories in general will love Borges' work.
There's also similar editions which collect all of Borges' poetry and non-fiction. The non-ficiton collection is also fantastic.