We saw Billy Elliott in NYC, but it is playing in London. If you do not know the theme, it concerns the conditions of the coal miners during a strike during Margaret Thatcher's time. The way of life for many was changed forever. If you go, be ready for in your face vulgar language by children and a theme involving homosexuality. None of that is just thrown in for shock effect though. That said, it is one of the most poignant and brilliantly performed shows we have seen. I would definitely go again.
We have seen Wicked in both London and NYC. While we liked it better in NYC, we enjoyed it both places. For that play, I recommend seats in dress circle rather than in the orchestra. A wide view of the stage is better.
Also, Le Mis is still showing in London. It was fantastic.