I find intertextuality interesting, as I like noticing the ways in which media texts have used certain aspects from another text, and adapted it to make it their own. I think intertextuality is a clever concept as it can take a specific aspect of a movie, and a director can "borrow" it and then adapt and improve it to their advantage.
An example of intertextuality is of the famous shower scene from the film "Pshyco", which has been "borrowed" many a time by other films.
A film that has used this scene from psycho, is the film The Stepfather (2010). The film has taken the idea from psycho and adapted and modernised it so that it takes a different turn. In the end we still see someone getting stabbed and ending up falling backwards into the bathtub and pulling the shower down with him. However it differs from Psycho as the "bad guy" is revealed and it is the "bad guy" who ends up dead in the bath.
I think this use of intertextuality is successful, as the director has taken a modern approach on the scene from psycho and has adapted it to make it more realistic and enjoyable for the target audience.