The most obvious revenge imagery in Hamlet is the Ghost of Hamlet's Father. The Ghost comes in on the first scene to set the stage (as it were) of the whole play. He comes in and says everything that Hamlet has secretly been thinking or worrying about in lurid detail and eggs Hamlet on to start down the spiral of madness he embarks on throughout the play.
After saying a lot of terrible things about Hamlet's uncle and mother, the Ghost uses the oldest parent guilt trip in the book, "If thou didst ever thy dear father love—". In other words, if you ever loved me you would do this thing for me, it's what I need you to do for me. How could Hamlet refuse his dead father's wish? So his fate is sealed.