$Vanguard Total International Stock ETF (VXUS.US)$ Personall...

Personally, I've been 50/50 by whole investing life and as you can imagine with the results I now understand Roger Gibson excellent line in his book "Asset Allocation", "Being truly diversified always means being unhappy, you will always hold too many of the losers and not enough of the winners". So far happy about U.S. and unhappy about foreign, but figure at some point that will change.