One point which I rarely see addressed in various internet fora is the striking similarity of form between orthodox Marxism and orthodox Objectivism. I realize this may be a repugnant idea to fans of either philosophy, but consider the following nutshell summary:

There are two classes of people in society. One class, which we call the ____, is productive and labors to bring forth all manner of useful things. The other class, which we call the ____, is not productive and, in fact, consists entirely of parasites who suck the life's blood out of their fellow men. These parasites accomplish their goal via exploitation and alienation: unjustly separating others from the fruits of their labor, though they wrap themselves in a philosophy by which they seek to justify their theft. One day, the revolution will come and the productive class will rise up and throw off the yoke of the parasites.

Broadly speaking, one can insert "poor" into the first blank and "rich" into the second and obtain the works of Marx. Or one can insert "rich" into the first blank and "poor" into the second and obtain the works of Rand.