Oh good! I was worried about you there...so where you put your funds is really about risk tolerance. From the TSP website:
The Government Securities Investment (G) Fund - The G Fund is invested in short-term U.S. Treasury securities. It gives you the opportunity to earn rates of interest similar to those of long-term Government securities with no risk of loss of principal. Payment of principal and interest is guaranteed by the U.S. Government. The interest rate paid by the G Fund securities is calculated monthly, based on the market yields of all U.S. Treasury securities with 4 or more years to maturity.
The Fixed Income Index Investment (F) Fund - The F Fund is invested in a bond index fund that tracks the Barclays Capital U.S. Aggregate Bond Index*. This is a broad index representing the U.S. Government, mortgage-backed, corporate, and foreign government sectors of the U.S. bond market. This fund offers you the opportunity to earn rates of return that exceed money market fund rates over the long term (particularly during periods of declining interest rates).
The Common Stock Index Investment (C) Fund - The C Fund is invested in a stock index fund that tracks the Standard & Poor's 500 (S&P 500) Index. This is a broad market index made up of the stocks of 500 large to medium-sized U.S. companies. It offers you the potential to earn the higher investment returns associated with equity investments.
The Small Capitalization Stock Index (S) Fund - The S Fund is invested in a stock index fund that tracks the Dow Jones U.S. Completion Total Stock Market (TSM) Index. This is a market index of small and medium-sized U.S. companies that are not included in the S&P 500 Index. It offers you the opportunity to earn potentially higher investment returns that are associated with "small cap" investments. The S Fund has greater volatility than the C Fund.
International Stock Index Investment (I) Fund - The I Fund is invested in a stock index fund that tracks the MCSI EAFE (Europe, Australasia, Far East) Index. This is a broad international market index, made up of primarily large companies in 22 developed countries. It gives you the opportunity to invest in international stock markets and to gain a global equity exposure in your portfolio.
I'm like you and have lots of irons in lots of fires (pension, DH's mil pension, Taxable account, Roth IRA's, Trad IRA's, and 529's). So if you are looking for safe, G is the way to go. But don't expect growth.
So it depends on what you are looking for. I have put everything into the L2040 fund and have been very happy with both it's performance and my lack of stressing out over allocation. But my safe money is in my pension and DH's pension. So we are comfortable with volatility in the TSP.