Somerset Maugham's stories had the quality of creating very very memorable characters. In fact a trememndous amount of effort was spent in building up characters, who probably often took priority over the plot!
A lot of his stories(The Ashenden Stories) were based on his one real life experiences as an intelligence agent during the second world war.
Two novels I would particularly like to recommend are the Moon and Sixpence based on the character of Paul Gaguin and the Razor's edge based on a character called Larry Evans