The "best" will differ from person to person depending on their situtation.

Pick a premium self defense load, make sure first that it functions in your gun and is accurate enough for self defense.

There are many fine loads but I will list the ones that I know have proven themselves on the street. That being said, there may be others that I don't know about.

Winchester Ranger T 127gr +P+
Corbon DPX
Remington Golden Saber 124gr +P or 147gr
Speer Gold Dot 124gr +P
Federal HST 147gr