Ray Bradbury is the best horror writer to have worked in a sci-fi milieu.
This story is one of only a couple sci-fi short stories to creep me out enough that I still remember them vividly decades later. (John Varley's "PRESS ENTER ■" is another.)
I forgot "Blood Music" was one of his. That along with "Press Enter" by John Varley are the two sci-fi stories that really freaked me out as a kid. The idea of having your body controlled and then rebuilt at the cellular/molecular level for the purposes of some emergent intelligence that arose from nanobots really got me.
On the more general Vinge theme, his "True Names" novella is probably overlooked compared to his novels. But, along with Varley's "Press Enter" (written about the same time) is a really good early take on the "Net" and its intersection with the real world.
Definitely near the top of my list. The sequel wasn't in the same class but his "True Names" novella is seminal cyberpunk although it doesn't have all of Gibson's trappings. (Varley's "Press Enter" is in a similar vein and has been more anthologized; they're both really good.)