When Dozois introduced the first of these retrospective anthologies a couple of years ago (THE GOOD OLD STUFF), I didn't buy it at first because of what I considered a hefty price tag for a paperback. Still, every year the best anthology of science fiction I buy is inevitably Dozois' Year's Best collection, so I have a great deal of respect for his selections. Finally, I broke down and bought that earlier volume, and I have bought each since (The Good New Stuff, Explorers, and now The Furthest Horizon).
Each of these volumes has been very well-packaged, and filled with some of the best classic science fiction short stories to be found anywhere, but in my opinion this newest volume is definitely the best yet. Granted, this is partly because all of the stories deal with one of my favorite science-fictional premises, the depiction of the extremely distant future. Even with such a seemingly-limited topic, Dozois has managed to assemble a varied and entertaining collection.
The real standout stories are Cordwainer Smith's "Alpha Ralpha Boulevard" , Jack Vance's "Guyal of Sfere" (originally part of The Dying Earth), James Tiptree, Jr.'s "Slow Music", and Ian McDonald's "The Days of Solomon Gursky", but there are also great works by Brian Aldiss, Frederik Pohl, Avram Davidson (a story I had never seen anywhere before), Walter Jon Williams, Robert Reed, Alexander Jablokov, and Poul Anderson.
This volume definitely goes on my permanent bookshelf. I cannot recommend it too highly.