Odysseus meets numerous people in the World of the Dead, including Tiresias, Agamemnon, Anticlea, Ajax, and Achilles. While the entire World of the Dead grouping is entrancing, a standout amongst the most engaging parts of it is Odysseus' experience with Achilles.
Achilles was, obviously, the legend of the Trojan War, the celebrated warrior who picked greatness in fight in return for a short life.