The following is an updated list from Meb Faber ranking every major stock market around the world from least to most expensive. It ranks the markets based on book value, cash flow, dividends and the CAPE P/E ratio.
While the United States has been the darling market in terms of performance since 2012, you can see it is now the second most expensive in the world. Brazil, which currently has my personal portfolio's attention, is now the least expensive. If you are a patient investor with a long time horizon, investing in less expensive stocks in less expensive countries has historically outperformed the more expensive markets over the long run. While I certainly would not put 100% of a portfolio into Brazil and Russia, it may be a good time to look for opportunities to diversify if your portfolio is heavily concentrated in the higher priced markets.
For more see: Brazilian Financial Markets In Complete Panic