Yu's translation is quite good, though I prefer the comic edge Arthur Weylan gives the story. Interestingly enough, Monkey does not eat a peach of immortality, but rather gains immortality from a guru, after which he destroys a peach banquet in heaven. Nor is his quest really a punishment (that is all a very western slant on the story) but an act of karma AFTER his imprisonment. The story, attributed to Wu Cheng-en, is quite hilarious on the surface, full of creatures, jokes and foibles, and on the other hand it is a deeply religious plot. This is the finest piece of Chinese literature I've come across.