At 1:16 38-43 seconds in Goodfellas a slight little line is right down the middle of the screen in a shot of Robert De Niro. This is chapter 27, when Paul Sorvino, Pauley and De Niro come to Ray Liotta's mistresse's apartment to straighten him out about her.
It's dead straight and very light little line for that 5 seconds. The shots are moving back and forth between the 3 guys. Next time it goes back to De Niro, it's gone.
Its on every release since the movies theatrical debut and is a known flaw in the master negative.