The performance by Ian McKellen proves that he is one of the best Shakesperean actors ever (and I've seen all the famous ones on the stage). Macbeth is not a complex character, just a fine man sucked into a downward spiral by his ambitious wife, but Shakespeare gives him really magnificent poetry to speak (Tomorrow, etc.), and McKellen says it all breathtakingly. Actually, some of Macbeth's lines are very difficult to understand, and McKellen is capable of the ultimate actor's magic of making the lines seem quite understandable as he speaks them (they go back to being difficult when you contemplate them on the page). His representation of the descent into madness is extremely effective, even though he goes quite far in this. Exactly how psychotic Macbeth becomes is one important question in interpreting this character, and McKellen (and Trevor Nunn, who directed) decide to go all the way. The other actors are all adequate, no problem. Judi Dench is not entirely convincing as the evil-from-the-outset Lady Macbeth, really a caricature and not a fully developed person in the play (Shakespeare's fault, not Judi's). Dame Judi is just not an evil person, and can't make us believe she is. However, at the most crucial point, the sleepwalking scene in the last act which precedes her suicide, she rises to the occasion. Her wail in unforgettable. This was originally a stage production, done in the round with few props, fine for this play, which is about words (and faces), not about setting. It's great that someone had the idea of filming the stage production, and doing it so well that it's possible to watch it. For many years this tape has only been available to educational institutions for $250, so it's great that everyone can see such a stunning performance now. And its great that Ian McKellen has become better known through X-Men and Lord of the Rings (though it takes Shakespeare to display his true talents).