The Boris Valejo art used on the paperback edition (taken from calendar/magazine?) - has been overlaid over the Woolhiser SFBC cover.

The Best of Leigh Brackett - Contents:
(Introduction by Edmond Hamilton - husband/editor)
The Jewel of Bas
The Vanishing Venusians
The Veil of Astellar
The Moon That Vanished
Enchantress of Venus
The Woman From Altair
The Last Days of Shandakor
Shannach - The Last
The Tweener
The Queer Ones
(Afterword by Leigh Brackett)

(some story summaries / teasers):
"The Jewel of Bas" - There's an ancient legend passed down among the people of the outermost planet. It tells of Bas the Immortal, possessor of the Stone of Destiny - a jewel of such power that owning it gives a man rule over the whole world. Ciaran and Mouse, two unscrupulous gypsies, only half-believed the story until they found themselves at the mercy of Bas's fierce android army... pawns in a sinister plan to enslave the human race.
"The Vanishing Venusians" - For years the space colonists had wandered the hellish eternal seas of Venus, seeking the home that was their birthright, death constantly stalking in their wake. And now they were making their final bid - three of their bravest fighting toward a promised land guarded by nightmare creatures. Who would emerge victorious? Close to 4000 desperate people waited anxiously for the answer...
"The Veil of Astellar" - Tough, hardbitten Steve Vance... once he was human! But three hundred years ago he betrayed his homeland for a race of alien vampires who fulfilled his every desire in return for a small "favor." All he had to do was lure innocent Earth spaceships to their doom on the vampires' world. He knew his soul was forever damned. But there was one way in which he might atone...
"The Queer Ones" - Hank Temple was at the editor's desk when the hospital called him in to see the X-rays. They were of a hill girl's illegitimate baby, and they showed insides like no child ever had. That was the beginning... and the end came on an enshrouded Ozark mountain, with deadly green lightning flickering and a sound in the sky that was not wind or thunder...

The stories originally appeared in Planet Stories, Thrilling Wonder Stories, Startling Stories, Magazine of F&SF and Venture - from 1944 through 1957. Only 2 stores overlap with previous collections - for most of these this is the first appearance in a Brackett book.