It's been a while since I read Fountainhead, but I think Atlas Shrugged lays out the concepts of objectivism more comprehensively, and the story is a bit more compelling.
In Fountainhead, I felt like Howard Roark was living by some principal, but couldn't quite articulate what it was.
IMO, the principle he wanted to live by was the same one all real conservatives want to live by: We want the government to leave us alone.