I've never read Atlas Shrugged - I couldn't take any more after The Fountainhead, which has to be the worst book I have ever read. Repellent philosophy,appalling writing and non-stop whinging.
Rand clearly stills rings bells with some people though. My review of The Fountainhead is probably my most read blog post ever.
http://ibanda.blogs.com/panchromatica/2005/01/the_fountainhea.html
If you want real libertarian fiction, with a hero who is a whole human being, with a joy in life that comes bursting off the page, who is full of good humour and gentility, who deeply cares for his fellow human beings and who avoids and subverts the state at every opportunity then read H E Bates' books about Pop Larkin, starting with The Darling Buds of May.