The Gunslinger, by Stephen King, is the first novel in the Dark Tower fantasy series. It was originally published in five sections in The Magazine of Fantasy and Science Fiction from 1978 to 1981. King later revised The Gunslinger to remove contradictions with following books. This novel, a fantasy western, follows the gunslinger Roland in his quest of the man in black, with numerous flashbacks to Roland's past that give the reader information about his past, if not too much insight to his character (which comes primarily via his actions).
The Gunslinger is highly stylized. It is filled to the brim with imagery, almost to the point of distraction for the reader. This gives the book a slower, deliberate pace and makes it reminiscent of a Sergio Leone/Clint Eastwood movie (which King acknowledges in his revised edition). All told, this is a fairly unique offering from the very versatile King, and is even stylistically unique among the books in this series. The original novel is more or less complete in itself; there is no cliffhanger ending.
The book is entertaining in and of itself, and works both as a stand-alone novel and as the introduction to the Dark Tower series.