X is for Xi You Ji - also known as Journey to the West (Epics from A to Z)

Come on, guys. Everybody knows the Monkey King, right?... Right?...

Origins
Journey to the West is one of the three great Chinese epics. It has existed in the oral tradition for hundreds of years, and it was also published in book format at the end of the 16th century. It takes place during the Tang Dynasty. It is an epic, mythical journey built on top of the historical event of Buddhism being brought to China.

The Heroes
The main hero of the story is supposed to be Xuanzang, a holy monk that is tasked by the emperor to travel to India and bring back the holy scriptures of Buddhism. He is very holy, very polite, very pure, and not exactly the survivor type. Here is the thing: Any demon who eats him gains immortality. That makes traveling for years through demon-infested lands a tad bit difficult.

Here is where the real hero (by centuries of popular vote) comes in: In order to protect the holy monk, bodyguards are ordered to accompany him. First and foremost, there is Sun Wukong, the Monkey King, the archetypal Trickster, who once broke havoc in the Heavens, ate the peaches of immortality, crossed his name out of the Book of Life and Death, robbed the treasury of the Dragon Kings, and defeated the celestial armies... until they dropped a mountain on him. A couple of centures later he was freed to help Xuanzang on his quest. In order to keep him in line, Sun Wukong is crowned with an iron band that the monk can tighten with a special prayer - he is, for all intents and purposes, leashed to him until the end.
The other bodyguards are Zhu Baije, most commonly known as Pigsy or Monk Pig, and Sha Wujing, or Friar Sand. Both of them used to be heavenly generals before they were exiled to Earth for various sins, and became demons; they both join the monk's quest seeking redemption. Pigsy it not the brightest bulb on the Christmas tree, and gets in trouble almost as often as he argues with Sun Wukong. He fights with a rake. Friar Sand is more quiet and obedient, and also less powerful than his companions.
In addition to the three misfits, there is also a hidden fourth companion: Yulong, a dragon prince, who is sentenced to be Xuanzang's steed in the form of a white horse.

The Highlights
I know I say this a lot, but it is really impossible to list all the highlights. The entire story is exciting, colorful, and all-around epic.
My favorite chapter is probably the one where the team encounters a den of female Spider Demons who capture the monk with silk threads they shoot from their belly buttons. It is a delightful mix of awkwardness (Xuanzang is kind of scared of women to begin with), terrifying magic abilities, and insect-involved fight scenes.
Another great moment is when Xuanzang and Pigsy accidentally drink from a spring in Women's Country, and they both become instantly pregnant (best monk freakout ever). In order to dissolve the magic pregnancy, they have to drink from another spring, protected by a demon. Sun Wukong takes the matter into his hands... after laughing his ass off.

Another famous moment of the epic is the tale of Princess Iron Fan, whose fan Monkey needs to steal in order to make a path across a mountain of flame. She proves to be a worthy opponent in a fight, together with her close-knit family of demons.
I also love the end of the story, when Sun Wukong asks to be released from the headband... just to find it is already gone.
Really, honestly, I could go on forever and ever. At one point I even ran a blog about this epic together with another storyteller, writing about our favorite scenes.
Just... go read the books.

Adaptations

Journey to the West literally has thousands of adaptations in cinema, TV, theater, song, and games. Monkey keeps popping up everywhere. Remember Goku in Dragon Ball? How about Jet Li in the Forbidden Kingdom? Some of my favorite takes on the story are the Japanese manga/anime Saiyuki, the post-apocalyptic video game Enslaved (with the talent of Andy Serkis bringing Monkey to life), Stephen Chow's recent movie adaptation (in the vein of Kung Fu Hustle), and, more recently, Zen Cho's short story Monkey King, Faerie Queen. Once you know the story, you'll see it everywhere!