The Mises Institute, who have reasons of their own

for a dislike of Ayn Rand, post a wonderful tribute to her in celebration of her centenary:

Ayn Rand's Contribution to the Cause of Freedom
by Roderick T. Long

Perhaps the most controversial aspect of Rand's philosophy—her rejection of altruism and her embrace of ethical egoism—is also one of the most misunderstood. Despite her sometimes misleading rhetoric about "the virtue of selfishness," the point of her egoism was not to advocate the pursuit of one's own interests at the expense of others', but rather to reject the entire conflictual model of interests according to which "the happiness of one man necessitates the injury of another," in favor of an older, more Aristotelean conception of self-interest as excellent human functioning.

It was on such Aristotelean grounds that she rejected not only the subordination of one's own interests to those of others (and it is this, rather than mere benevolence, that she labeled "altruism") but also the subordination of others' interests to one's own (which she labeled "selfishness without a self"). For Rand, the Aristotelean recognition of properly understood human interests as rationally harmonious was the essential foundation for a free society.

I've cited the points that I consider most important, but you may find other points more worthy of your attention. Read, as they say, the whole thing.