Ayn Rand has some great ideas, but they make certain assumptions about human nature that are quite simply not true (which is the same problem with capitalism).
I always make a point to reply whenever I see her mentioned on HN, because her philosophy helped me out of a very messy series of life crises, and I hope someone else struggling to figure things out sees my comment and is inspired to take a look.
But as for how the characters behaved and reacted to each other, it seemed too robot-like and lacking empathy that The Fountainhead, for example, literally had me tossing the book across the room multiple times.
"Real people don't act like that!" I remembered saying. And that was in high school, when I was Libertarian. I still finished the book though.
If someone wants to check her out, I think Anthem is the one to read. You get all of her ideas, pretty much, with the bonus of being able to get through it in a few hours. Her other books are way too long-winded. The Fountainhead, despite being infuriating and having some excessive diatribes, I did think was a good book overall.
Personally, of all the high school reading I did, Walden had a much more lasting effect on me than Ayn Rand did.
Click around here if you're curious: http://aynrandlexicon.com/book/conceptual.html.