So I've been doing a lot of research into varying brands & ballistics for both the 9mm & 45acp calibers. Most of what I've found in forums is either uninformed opinion, based on a lack of understanding, or uninformative & poorly presented opinion. It seems many brands purposefully omit certain stats that are crucial in selection for anyone actually trying to make an informed decision. Some sites list pertinent info such as barrel length(s) tested and penetration depth. Most just talk like people with paper a-holes (Critical Defense). What I've determined is the following for personal defense in modern "concealed carry" sized pistols (aka pocket pistols or mouse guns).
Best 9mm, for penetration through possible barriers (including clothing, glass, sheet rock & metal), reliable expansion & maintained velocity from shorter barrels is the Cor-Bon DPX 95gr solid copper. Manufacturer tested in 3.1in barrel.
Best 45acp, for same reasons above, is the Federal HydraShok 185gr JHP. Tested in 3.6 & 3.75 in barrels by two individual sources. 230gr recommended for longer barrels.
Now none of this can account for the gun's side of things. One should still test cycle reliability, grouping accuracy & expansion with each of their firearms. This is just an in general, broad scope determination based on my exhausting research and ballistics graphing taken from several different sources provided from individual user experiences and manufacturer reports.
*There are some very good non-standard rounds that I didn't include in my findings because I refuse to put the undue pressure on my guns, but the best I settled on was the Cor-Bon 115gr +P JHP 9mm and Speer Gold Dot for either 9mm or 45acp.
There's also some great info & recommendations on the following site, but without the precise stats I had to look further, and I'm glad I did... http://www.chuckhawks.com/ammo_by_anonymous.htm
Any further enlightening info from more educated and experienced users would be welcome. This is just what I've gathered from as many sources as I could find through my searches. There are plenty of other great brands, but I could find no statistical proof to back user claims and just saying that the FBI had been using them for years means nothing to me, I work on math only!