|I second Peter Reidy's praise for Kay Nolte Smith's Tale of the Wind. Unlike Peter, I think her other novels are worth reading as well.|
Like Jeff Perren, I find Sarah's question a little vague. Sarah, if you're looking for fiction that shows a Randian influence or which resembles Rand's fiction in certain ways, check out my recent article in the Journal of Ayn Rand Studies on "Ayn Rand's Influence on American Popular Fiction." It discusses dozens of recent novels that show that influence.
If you'd be happy with fiction that displays broadly libertarian, though not specifically Randian, values, I cannot recommend Ken Kesey's two novels -- One Flew Over the Cuckoo's Nest and Sometimes a Great Notion -- too highly. Sometimes a Great Notion is the more impressive of the two. It may well be the long sought Great American Novel. Another broadly libertarian novel of very, very high quality is The Fool's Progress by the late Edward Abbey.
If, as you insist, you simply want "anything with a glimmer of value," anything "from the 20th century that made [me] say 'wow'" -- if you just "want to know that someone alive today, or not long ago, has made something worth reading" -- then I must confess I'm somewhat baffled by your predicament. The 20th Century is far and away the most magnificent century of achievement in fiction in our language in the entire history of fiction. There's no shortage of outstanding stuff here. It's all around us, in boundless profusion.
Have you read the greatest of all American novelists, William Faulkner? If not, try Light in August or Absalom, Absalom! followed by The Sound & the Fury. Have you read Vladimir Nabokov's Pale Fire? It's the most amazingly intricate and amazingly clever piece of fiction I've ever read -- a true masterwork.
Among immediately contemporary (living) fiction writers, several authors of science fiction and fantasy stand out as having made a particularly noteworthy contribution to American literature. Have you read Gene Wolfe? I highly recommend his early novel The Fifth Head of Cerberus, as well as his four-volume Book of the New Sun. Then there's Samuel R. Delany. His four-volume work Return to Neveryon (the first volume is Tales from Neveryon) is one of the great works of art of the 20th Century and an amazingly insightful fictional meditation on the evolution of human society.
I can go on like this for pages and pages and hours and hours. Maybe if you rattled off a list of novels or stories that have blown you away in the past, I could get a better feel for the kind of thing you like best.