The Berkley Showcase was a "house" anthology, put together by the editors of Berkley Books as a non-profit venture, supplementing the 5-titles a month schedule of successful books by Heinlein, Herbert, White, and others, with an eye toward discovering and developing new talent. The editors provide brief story introductions and biographical notes throughout the series, though only the first volume has a book introduction. Aside from the stories, Volume #2 includes an interview with Barry B. Longyear, Volume #3 a profile of Theodore Sturgeon by Paul Williams, Volume #4 an interview with Elizabeth A. Lynn.
Jack Dann's story in Vol. 3 was a Nebula nominee; Jack Dann's in volume 4 was a WFA finalist; several others placed on Locus Polls.
Most frequent authors: Ronald Anthony Cross (4), then Thomas M. Disch and Karl Hansen (3 each).
The Berkley Showcase Vol. 1, Victoria Schochet & John Silbersack, eds. (Berkley, 1980)
[isfdb]
The Berkley Showcase Vol. 2, Victoria Schochet & John Silbersack, eds. (Berkley, 1980)
[isfdb]
The Berkley Showcase Vol. 3, Victoria Schochet & John Silbersack, eds. (Berkley, 1981)
[isfdb]
The Berkley Showcase Vol. 4, Victoria Schochet & John Silbersack, eds. (Berkley, 1981)
[isfdb]
The Berkley Showcase Vol. 5, Victoria Schochet & Melissa Singer, eds. (Berkley, 1982)
[isfdb]