If you feel the need to move money into investments to obtain some yield, you may want to make sure you cover the major asset classes to reduce volatility. This My Money Blog post
has a good list of the major asset classes which include US stocks, international stocks, REITs, US bonds and gold. For each asset class the annual total returns from 1 month to 10 years are listed. As mentioned in the post, the point isn't to chase performance, but it's to help with rebalancing which means to invest more in the underperforming asset classes.
The three asset classes that have the best 10-year returns are: 1) emerging markets (14.68%), 2) REITs (11.22%) and 3) US Treasury Bonds - long term (8.54%).