Anne McCaffrey 1926-2011
Anne McCaffrey was without doubt one of the five writers who most influenced my reading of science fiction and fantasy. Where many people see Pern as fantasy dressed up as science fiction, (with an implicit sneer, as if that's a bad thing) I see fantasy transformed into the science fiction idiom, with all the necessary rigor that entails.
This is particularly true in the earliest Pern stories and books, which feature not only science, but sophisticated politics and characters who need cunning, not magic, to save themselves. If you start with the The Dragonriders of Pern, you find yourself plunked into a medieval society sorely in need of scientific advancement and, dare we say, enlightenment. Just look at how poor Menolly is treated at the beginning of the Harper Hall trilogy.
Along with the Pern books, I most fondly remember Crystal Singer and Killashandra, two lovely and original science fiction romances.
She will live on in the pantheon of the greats.