Best known for her Dragonriders of Pern series, Anne wrote many other novels (I particularly remember her Crystal Singer books). She was one of the Grand Dames of SF, a powerful presence in the field for decades. She created some of the most enduring images in SF, and also one of the most perfect "both sides of the line" series, as Dragonriders (despite an SF prologue) seems almost pure-quill fantasy, and slowly goes more SF as time goes on.
Her dragons in particular were influential, and if they did not truly INVENT, they at least made into a powerful trope the idea of a personal, mind-to-mind bonding with some other creature as a friend, ally, and companion. I don't think Honor Harrington would have her Nimitz if it wasn't for her, and I suspect many other stories would lose such creatures as well.
I almost met her once -- when she was to be GoH at Albacon. But she was unable to come at the last minute.
Farewell, Anne. May there be a Weyr for you somewhere in the beyond.