If you're seeing things running through your head, who can you call?
I love Banquo's ghost. He's one of the most dramatic ghosts out there, popping up all covered in blood and totally invisible to everyone else. I absolutely love the line "Never shake thy gory locks at me!" and try to use it in everyday conversation as often as possible, which is not easy given the general lack of gory lock-shaking that happens on a day-to-day basis.
As far as staging is concerned, there's always a question of whether or not the audience should see Banquo's ghost. After all, nobody else at the dinner can see it. In Ian McKellen's version, Banquo is completely invisible and, for all we know, entirely a product of Macbeth's guilty and disintegrating mind. McKellen goes full-throttle crazy here, and is almost uncomfortable to watch. Very effective.
In the production starring Patrick Stewart, director Rupert Goold decided to split the difference. The banquet scene was staged twice, once before intermission and once afterwards. Before intermission, Banquo was visible. After intermission... he was not. In the filmed version they accommodate this by cutting between visible and invisible Banquo.
The winner of the "gory locks" award goes, unsurprisingly, to Roman Polanski's film.
Now THOSE are gory locks.
Dramatis Personae | Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8 | Part 9 | Part 10 | Part 11 | Part 12 | Part 13 | Part 14 | Part 15 | Part 16 | Part 17 | Part 18 | Part 19 | Part 20 | Part 21 | Part 22 | Part 23 | Part 24 | Part 25 | Part 26 | Part 27 | Part 28 | Part 29 | Part 30