Most famous for his novel The Catcher in the Rye, Salinger was best known in the house I grew up in as the author of the book with all those GDs in it. The obscenity spouted by teenage character Holden Caulfield got a lot of attention in 1951, but it's probably Caulfield's distrust of authority figures and dissatisfaction with the artificial nature of human interaction that continues to make it controversial. At my high school in Lubbock Texas (in 2000, mind you) I remember my teacher having to encourage us to read the book by presenting it as a semi-covert extra credit opportunity rather than assigning us to read it.
Catcher also reportedly encouraged Mark David Chapman to murder John Lennon (though I'm pretty sure Chapman was messed up long before he read about Caulfield's hatred of "phonies") and the cultish response the book must have at least in part pushed Salinger into reclusiveness (though his early writing indicates his misanthropy preceded his fame). Accounts of his strange behavior and general old cussedness aren't really relevant when you're discussing his work, though. He hadn't published anything since the mid-'60s, and his main interaction with the outside world in recent years has been via lawsuits to prevent biographies and unauthorized Catcher sequels from being published, so it's hard to claim the literary world will suffer much from this old man's death, but we've definitely lost a great thinker and a man who was once a great artist. I'll remember him best for Franny and Zooey, a much more subdued account of the pain of being strange and idealistic in a hateful world, and for his short story "A Perfect Day for a Bananafish," (read it here) which I've reread several times, but still couldn't really tell you what it's about. I also can't argue with the many people I've talked to over the years who said it's one of the best stories they've ever read.
May all such intelligent, creative, damaged people die peacefully at an old age after lives lived on their own terms.