i agree that "best" is subjective in regards to ammo.
i would look for what works reliablily each and every time the trigger is pulled. the best penetration, the fastest, the most accurate, or the largest expanding ammo is pretty much a moot point if it doesn't feed well or jams in your pistol.
i use either the Speer Gold Dot 124 gr. JHP, or the Hornady 124 gr. XTP ammo in my 9mm pistol. both work quite well with no problems.
CIA, FBI, NSA, GOP, ACLU, NIA, DOJ, DOD, FEMA, GOA, DOT, NASA, CDC, DARPA, DIA, NOAA, NRC, HUD, IRS, BLM, OSHA, EPA, SEC, SSA, TSA..........