The language and the characters. In other words, not really the plots (though they are really good as well).
And the sheer depth. It's not just Shakespeare's genius that's mind-blowing but also that the audiences at the time understood it. Really made me think how thick popular audiences are these days in comparison
The other day when we were in London we met up with my ex-flatmate, he (inevitably) lives on a house-boat now, but his girlfriend works at the National Theatre and she told us that a new play - Much Ado About Nothing - was just about to start and that if we rang early enough we might be able to get tickets for the opening night, which is press day. That's a good thing to do cos turns out the tickets on that night cost between ten and twenty quid, whereas on the other nights the cheapest ticket anywhere is forty-six pound (which is too much if you ask me, I honestly don't think you get forty six pounds worth of entertainment from an ancient two hour comedy play). There were only two seats left, one in the stalls and one in the circle but we got them anyway.
That day I had to go into town and buy some lego for my nieces, I got really drunk and then went to Hamleys which was a truly nightmarish experience. Then I rolled up to the National and managed to neck one more wine before the performance. I was right at the front and... I guess this is the point that responds to the quote above; I really enjoy Hamlet, Macbeth etc, death is still tragic I guess, but I don't think that Shakey's comedies stand up in the same way, there is the odd good bit, but in my experience of going to see his comedies in the theatre you get this really performative thing from certain people in the crowd who laugh really loudly at the jokes to show that they have understood them - which to me is somehow the antithesis of what BB is talking about above. Instead of an intelligent audience grasping a complex double-meaning and reference on the fly you've got some pretentious people who've studied in advance trying to convince everyone that they're doing that. And also lots of lines have been twisted to bring out innuendos which weren't there in the original (I guess to make up for ancient ones that have been lost) and you're thinking, are we really reduced to making jokes out of the word "come" that Shakespeare almost certainly didn't intend. Not his fault by the way, I'm sure that they were funnier at the time but language has moved on and humour has moved on and lots of it just doesn't really work, so extra laughs have to be eked out wherever possible.
I'm not saying that I didn't enjoy it. I did. But I'm glad I didn't pay fifty bob. I was right at the front and several seats nearby were empty, I guess some ticket holders had simply not turned up, which seems a bit unfair when it was such a scramble to get tickets and many must have been disappointed. On the other hand it was handy cos I managed to smuggle Liza down from the circle at half time to sit with me. Also at the end there was a party for the cast and our friend told us that noone was checking so we went into that and got stuck into the free booze and luxurious canapes.
It was a cool evening and everything but if it had been Lear or Othello or something I would have really loved it in a completely different way I'm sure.