The only 'dollar based' investment that I see as anywhere near fair value is US property. Although property always undershoots fair value on the way to its market bottom.
So around another 10-15% off and US property will be heading towards cheap status verses its historical (using a yield and price too earnings measures).
The US market indexes are overvalued in my opinion on a 10 year cyclically adjusted P/E basis and on a price to book basis.