In Wuthering Heights, Heathcliff wants revenge on everyone including Edgar, Hindley, and Cathy. What are some examples of revenge?

You have identified a key theme in this excellent novel.
What is more disturbing when we think about it is the way that revenge is passed on down
through the generations and is used to harm and damage the lives of the young heirs of
Thrushcross Grange and Wuthering Heights. It is clear that one of the principal
characters who wants and gets revenge is Heathcliff, and in particular we see that he
gets his revenge against Hindley, for example, by treating his son in precisely the same
way that Hindley treated him, reducing Hareton to nothing better than an ill-speaking
slave that is uneducated. Likewise he gets his revenge against Edgar by marrying his son
to Edgar's beloved daughter and making sure that Cathy cannot be there for her father's
death. This also enables Heathcliff to inherit Thrushcross Grange. Revenge is something
that is shown to echo down throughout the generations.