Since I have discovered 16 of Robert E. Howard's stories online (legally I hope), I have been furiously reading them. Seven of those stories involve Conan, Howard's famous barbarian. Even though the Hollywood Conan may be more famous than REH's version. Also included are seven tales of Solomon Kane, the strange puritan adventurer who's strange brand of religious justice took him to the far reaches of the world. If you are interested in reading the origianl Conan, I would suggest reading 'Jewel of Gwahlur', 'Beyond the Black Coast'. More on the good ones as I read them.
That leaves two stories, bothof which are fantasy based but don't involve any of REH's major characters. Of these two I have read 'The Valley of the Worm'. It is very interesting, but not totally unique. It could just have easily been a Conan Story