The Year's Best SF Anthology Series: A Potted History
This is a brief sketch of all "the year's best SF anthology series" I know of, followed by an annotated table of them. Primary sources are my own collection, the ISFDB, and the SFE. By the quoted phrase, I mean anthologies of more than one volume, each of which are made up of English-language short science fiction reprinted from a given year with no further restriction on their contents.
As far as I know, this form was pioneered in SF by Bleiler and Dikty (later just Dikty) who covered 1948-57 (with companion volumes of longer stories covering '51-53, though skipping '56 altogether). I've never read (or so much as seen) one of these.
Then Judith Merril covered 1955-66 with her eclectic proto-new wavy and new wavy anthologies. She sought out fantasy and surrealism and what might now be called slipstream from slicks and "little" mags and even published poems and cartoons along with actual SF from actual SF magazines.
Wollheim and Carr covered 1964-70 together and started an interesting nexus. When Wollheim left Ace to start DAW in 1972, he also started his own annual series (with Arthur W. Saha) which covered '71-89, while Carr left to do one for Ballantine, covering '71-86. (Meanwhile, Ace had Pohl do an anthology that year (9/72) and Ackerman the next (6/73) before giving up and adopting del Rey's annual (Dutton, 7/72; Ace, 8/73).) Beginning in 1979, Wollheim also got Asimov and Greenberg to edit retro-annuals, so to speak, which covered 1939-63. In this way, there's an unbroken string of Wollheim-related annuals from 1939-89. Carr is probably a little more new wavy and literary but in a tastefully restrained way while Wollheim tends more towards popular stories and Asimov/Greenberg have the advantage of hindsight and collect from a classic era so are, naturally, classic.
Right after Wollheim and Carr started, the Nebula anthologies began, covering 1965 to the present. They're not exactly identical to the other annuals, being chosen from award slates and changing their remit over time but basically meet the definition I gave above. That award slate is, of course, chosen by the SFWA and naturally tends toward more "writerly" stories.
In the UK, Harrison and Aldiss collaborated to cover 1967-75 but I've never seen/read one, nor one of David S. Garnett's much later (1988-90) series of "Orbit Yearbooks." (Also in the UK, Edmund Crispin had edited a series called Best SF [N] intermittently from 1955-70 but they are not annuals, covering random years in addition to their random releases and I know nothing else about them.)
As alluded to, 1972 (the year of the Wollheim/Carr split) saw the addition of a sixth SF annual when Lester del Rey started his. He covered 1971-75 before turning the reins over to Gardner Dozois from 1976-80. I've never read one of the del Reys but the Dozois' are a bit new wavy and 70s generational. After a brief intermission, Dozois started a new annual that began by covering 1983 and is still running. It was much more 80s-oriented (even coining "cyberpunk" while featuring probably even more "humanist" stories) and has gone on to become The Standard Annual. He tends to favor more literary stories and is not an Analog fan but also likes a good rip-roarin' yarn.
After a peak of six annuals in 1971-72 and the deaths of Carr and Wollheim in the late 80s, SF annuals reached their scarcest point from 1990-94, during which there were only the Dozois and Nebula annuals. (Perhaps not coincidentally, this was around the time of The Second Great Magazine Collapse.)
In 1995, Hartwell (with Cramer later receiving credit) began his series. Dozois and Carr arguably fought over some of the same territory with Wollheim off to the side, but with Dozois being more of a "young turk" than even Carr. Later, during his lonely years, Dozois may have drifted a little to the fantasy/artsy side such that Hartwell came in with the mission of representing "the best science fiction.... Not fantasy. Not science fantasy. Science fiction...", which may have resulted in Dozois getting a little more rigorously science fictional again. As part of the general war by publishers on their own mass market paperbacks, when Hartwell's annual shifted publishers in 2013, it was given a format change to trade paper. Also, perhaps not coincidentally, that edition was its last.
From 2001-04 Science Fiction: The Best of [Year] was edited by Haber with Silverberg (first two) or Strahan (last two). Strahan then started his own series which covered both SF and F from 2006 to the present, though it changed publishers en route. Meanwhile, Horton had started his coverage with 2005 and it continues to the present though it was merged with his fantasy annuals in 2008.
2015-16 gave us our first new annual anthologies in a while, with Baen presenting David Afsharirad's The Year's Best Military and Adventure SF (which should be excluded as having thematically restricted contents, but is an interesting enough development that I've listed it anyway) and Night Shade Books finally replacing the Strahan with Neil Clarke's The Best Science Fiction of the Year. With those, there are now three annuals completely devoted to SF, along with Strahan's, Horton's, and the SFWA's SF/F hybrid annuals.
|The Best Science Fiction Stories: [Year]||1949-58||Frederick Fell||Bleiler/Dikty||1|
|The [Nth] Annual of the Year's Best S-F||1956-68||Simon & Schuster||Merril||2|
|World's Best Science Fiction: [Year]||1965-71||Ace||Wollheim/Carr|
|Nebula Award Stories||1966-||Various||Various||3|
|Best SF: [Year]||1968-76||Sphere||Harrison/Aldiss||4|
|Best Science Fiction for [Year]||1972-73||Ace||Pohl; Ackerman|
|Best Science Fiction Stories of the Year: [Nth] Annual Collection||1972-81||Dutton||del Rey; Dozois||5|
|The Best Science Fiction of the Year #[N]||1972-87||Ballantine||Carr||6|
|The [Year] Annual World's Best SF||1972-90||DAW||Wollheim/Saha|
|The Great Science Fiction Stories Volume [N, YEAR]||1979-92||DAW||Asimov/Greenberg||7|
|The Year's Best Science Fiction: [Nth] Annual Collection||1984-||St. Martin's||Dozois||8|
|The Orbit Science Fiction Yearbook [N]||1988-90||Orbit||Garnett|
|Year's Best SF [N]||1996-2013||HarperPrism||Hartwell||9|
|Science Fiction: The Best of [YEAR]||2002-05||ibooks||Silverberg/Haber||10|
|Science Fiction: The Best of the Year, [Year] Edition||2006-||Prime Books||Horton||11|
|The Best Science Fiction and Fantasy of the Year: Volume [N]||2007-||Solaris||Strahan||12|
|The Year's Best Military and Adventure SF [Year]||2015-||Baen||Afsharirad||13|
|The Best Science Fiction of the Year: Volume [N]||2016-||Night Shade Books||Clarke|
 This was accompanied by Year's Best Science Fiction Novels: [Year] from 1952-54 before Bleiler dropped out and the two series were merged and renamed to Best Science Fiction Stories and Novels: [Year] in 1955 and 1956. Finally, after skipping a year and changing publishers to Advent, it was renamed to Best Science Fiction Stories and Novels: 9th Series in 1958. By "novels", novellas and even novelettes are meant.
 This series had various names but took this form more often than others (for all middle five by Simon & Schuster and one later one). The first four volumes were published by Gnome, and the last three by Delacorte.
 This has had too many publishers, too many titles, and too many editors (the last by design, at least) to bother detailing. For the past several years, it has also usually run a year or two behind and, due to the "rolling eligibility" rule, doesn't always restrict itself to a single year. But, initially and for many years thereafter, it was released punctually and dealt with a specific year.
 In various years various American publishers sometimes published it before Sphere. In its final year, it moved to Orbit in paperback, received a hardcover printing from Weidenfeld & Nicolson and got a name change to The Year's Best Science Fiction No. 9.
 Del Rey edited the first five volumes through 1976; Dozois edited the final five through 1981. They were published by Ace in paperback until moving to Dell paperbacks for #7-8 (1978-79) and then failing to find a paperback publisher for the last two volumes. (Incidentally, this sets up an Ace nexus akin to the Wollheim nexus, except that it's basically meaningless. Still mildly interesting in an odd way: since Wollheim got his start in annual editing with Ace and annuals from 1939-89 have a Wollheim connection, and Ace was the paperback publisher of a single Dozois annual (though he actually got his start in annual editing in hardcover at Dutton) and his second series of annuals continues to this day, there is a trace Ace connection to annuals from 1939 to the present.)
 The first one wasn't numbered. Beginning with #6, the paperback imprint changed its name to Del Rey (still part of Ballantine) and, incidentally, it received a hardcover publication from Holt, Rinehart and Winston that year. #8 and #9 contained no novellas but were accompanied by The Best Science Fiction Novellas of the Year #1 and #2. With #10 it moved to Timescape (part of Pocket). With #13 it moved to Baen. With #14 it moved to Tor and was called Terry Carr's Best Science Fiction of the Year that year, Terry Carr's Best Science Fiction of the Year #15 the next, and Terry Carr's Best Science Fiction and Fantasy of the Year #16 in its final year.
 The YEAR in the title is the year covered rather than the year published. And, technically, the full title is Isaac Asimov Presents, etc. Beginning with #12, the "Volume" was dropped and the year was placed in parentheses and, beginning with #13, the number received a hash mark, i.e., Isaac Asimov Presents the Great SF Stories #13 (1951). Incidentally, in 2002, NESFA published Robert Silverberg Presents the Great SF Stories: 1964, edited by Silverberg/Greenberg in an effort to keep the series going outside of DAW (and overlapping in time with an already existing Wollheim/Carr though the new volume's fifteen stories contain only three overlaps with the seventeen in the original volume) but there were no further volumes.
 The first three volumes were published by Bluejay (with the third also receiving an SFBC publication). St. Martin's became St. Martin's Griffin even for the hardcover publication beginning with #20.
 Kathryn Cramer (who had apparently been involved all along) received co-credit beginning with #7. Though all under the same umbrella, the imprint changed to Eos/HarperCollins with #5, Eos with #12, and Harper Voyager with #16. However, with #18, it was published by Tor without (crediting?) Cramer. The replacement of the $8 500-page mass market paperback with a $16 400-page trade paper probably did not help sales and hastened its demise.
 The year in the title is the year covered rather than the year published. The third and fourth volumes were edited by Haber/Strahan.
 This was merged with the fantasy series in 2010 and renamed The Year's Best Science Fiction & Fantasy [Year]. The "Edition" was restored in 2013, i.e., The Year's Best Science Fiction & Fantasy: 2013 Edition.
 The first seven volumes of this series were published by Nightshade but it moved to Solaris for #8. As far as some of this editor's ambiguous anthologies, in 2006, the year between the last Haber/Strahan and the first of Strahan's series, Locus Press published Strahan's Science Fiction: The Very Best of 2005 which is otherwise unrelated to anything else. Also, from 2004-07, the SFBC published Strahan's Best Short Novels [Year] which doesn't seem to be a companion to any given series but is restricted to novellas. (Similarly, Paula Guran (really a horror editor) began The Year's Best Science Fiction & Fantasy Novellas [Year] for Prime Books in 2015 but that is also restricted, without a companion volume.) Also, Strahan published several volumes of an Australian annual but I see that as an annual series of theme anthologies.
 The first volume was called The Year's Best Military SF and Space Opera but was modified for the second volume to better reflect the somewhat broader contents.