Beg, borrow or steal to get a ticket to The Last Days of Judas Iscariot at the Almeida.  Fantastic play, the ultimate thesis of which is that there is no hell but that which we create for ourselves.  Hear, hear.  It's tremendously funny, completely absorbing, and I've never had three hours pass so quickly.  Go, what are you still reading for, go!

I also saw The 39 Steps in the West End (also playing Broadway, it seems).  Saw it with my dad and brother, both of whom loved it.  It's very funny, goes a bit amiss in the second act, but a great family play.  There was a kid sitting behind me who seemed to have a blast.

But go see Judas.  Support the Almeida.  Go on, I'll wait.