SOLOMON KANE in the 1995 paperback edition I like best, cover by Ken Kelly, who did many of the Warren magazine covers in the 1970's.
With an introduction and 4 stories completed from Howard fragments by horror writer Ramsey Campbell, I think more successfully expanded than in any other attempt to finish these incomplete Howard works.

Specifically Ramsey Campbell completed the story fragments for:
* "Castle of the Devil" (the 5th chronological story)
* "Death's Black Riders" (the 6th story)
* "Hawk of Basti" (the 11th story)
* "The Children of Asshur" (the 15th story)

Of the 16 original Howard stories in the book.

While Howard died in 1936, several of these stories remained unpublished until 1968 and 1979. And only completed in this 1995 book, 60 years later.