Some of them are pretty obscure. I tried to read both Cybleline and Coriolanus in college and couldn't get through them. I've never tried King John, mostly because my English Major friends said that its really awful. Dito for Henry VIII.

But I had read almost all of the comedies and most of the tragedies and some of the problem plays by the time I got to highschool. It took me longer to get into the histories. My mother started my out early by reading The Tempest and A Midsummernight's Dream out loud to me when I was 9.