Rating games, or rate-the-one-above-you games, are TBGs in which one must rate the post above them and then provide content in their post for the next player to rate. Many variations upon this simple formula exist.
Many different types of rating games exist, on a variety of different themes. A popular variation is to have a phrase with blanks inserted, and the player must fill in the blanks to create an amusing phrase.
Another variation is often called "9001 things" or "1000 things" or any other, similar, variation. The titles of these games are often "9001 ways to XXX" or "1000 reasons to XXX" and the player must create a new addition in their post to a list that matches the theme of the game.
Even the most basic topics can be made into a game by simply adding the rule "rate the one above you". For example, a topic about ASCII art or usernames could become a rating game.