Ayn Rand and her works were known for some pretty anvilicious messages, often involving human freedoms and capitalism. When a character goes on a long rant about any of these topics and their importance, it would be defined as an Ayn Rant. Examples include Andrew Ryan's introduction of Rapture (Bioshock), actual Randian speeches (like those found in Atlas Shrugged)and Knight Kemplar speeches in general.
Hello, Unknown Troper. You'll need to get known to lend a hand here.