Each year, Gardner Dozois' Year's Best Science Fiction anthology wins plaudits for the quality and scope of its selections, not to mention its artful blend of new faces and crowd-pleasing veterans. (The summation of the year and recommended reading list have also become must-read items for devotees of the genre.) This 19th installment includes works by Nancy Kress, Robert Reed, Geoff Ryman, Allen Steele, Michael Cassott, and many others.