Stanislaw Lem, one of the greatest of the greatest of Science Fiction writing, has died yesterday at the age of 84. In the West, his best known work is undoubtedly Solaris, though I liked the original Tarkovsky movie version better than the more recent George Clooney film.
However, my personal favourite of Lem's works is his least characteristic, the absolutely amazing and terrifying The Invincible, which I have read quite a few times and need to read again now that I am an adult.
His trilogy about Ijon Tichy (The Futurological Congress: From the Memoirs of Ijon Tichy, Star Diaries: Further Reminiscences Of Ijon Tichy and Memoirs of a Space Traveler: Further Reminiscences of Ijon Tichy) is also a great read, a SF satire at its best.
You can learn more about Lem here.