Jack Vance has offered many unforgettable masterpieces to the Fantasy and SF genres, and this may be his greatest. It is the second book of the Dying Earth quartet, but can be read first. The first novel in the series, "Mazirian the Magician," is composed of short stories which share a setting but no plot or characters with the Cugel novels.
If you are a fantasy fan, you should read this book. If you like the idea of fantasy, but are sick of Tolkein/Howard knockoffs, then you must read this book. It contains two of the greatest characters in fantasy: the amoral trickster Cugel, and the devious Laughing Magician. Over the course of the novel, Cugel negotiates a series of obstacles, mostly solved by manipulating the irrational taboos of the societies that he encounters. The novel is fascinating, fast-paced, hilarious, suspenseful, and creative.
As a trivia note, the Dying Earth books were favorites of Gygax and Arneson and influenced the formation of D&D.