The choices for investors looking for safer returns with higher yields away from Treasury bonds generally will turn to investment grade corporate bonds first.
The list is long and sometimes quite repetitive, as components vary little one to another. The real choice here is maturity selection or which duration risk you are willing to assume? The longer out the curve you go, the greater the return and risk to principal.
Again, I'm really not in favor of bonds now. It may be that I suffer from the "the more you know about something, the less you like it" syndrome. Nevertheless, as I wrote in the beginning, yields are skimpy and risks from budding inflation is high with longer maturities. With shorter maturities, you do little better than yields from the bank after headline inflation. So, given the environment, with many uncertainties, "cash" from money market funds and/or T-Bills is just fine for now.
Remember, many institutions (insurance companies, pension plans and many asset allocation models) call for large bond allocations. Some insurance companies may only own bonds, given their actuarial table requirements. If you're an individual investor you're not under the same pressures, no matter what you hear in the media.Further previous non-correlations of bonds to stocks, for example, have been whittled away, given current monetary policies of the Fed. This only adds to risks already mentioned. If you must buy them, our bias generally is to more liquid issues unless we utilize them in Lazy portfolio approaches. Just always remember ETF sponsors must issue and many times their interests aren't aligned with yours. They have a business interest and wish to have a competitive presence in any popular sector. For further information about portfolio structures using retail or other ETFs see