All stage performances, no film, so don't go wondering where Mel Gibson and Kenneth Brannagh place on the list. They don't. This list is reserved for the likes of Jacobi, Barrymore, Gielgud and others. I knew that John Wilks Booth's brother had been performing Hamlet the night that Lincoln was shot, but I had no idea that he was "considered the greatest Hamlet of his generation."
The idea of calling a stage performance one of the greatest of a generation is an interesting idea to us now in a world of DVDs and Tivos where we can go pause, go backward, and watch over and over again. These were real people performing live. If you missed it, well, you missed it.