Just reading this again and trying to figure out what you were asking exactly. Do you mean what is most reliable, cheapest, for plinking, or best for defense/hunting?
I have run PMC bronze, federal, lake city and my own hand loads through mine and only had one issue (primer related). So I think everything shoots well out it, is reliable and is very accurate so get your hands on whatever you can for as cheap as you can. As a side note I wont shoot steel cased ammo out of any of my guns unless things have gone really bad.
If its hunting or an HD question I would go with anything that has a ballistic tip, soft point or a hollow point. At about 2330 FPS (what my hand loads were coming out at and factory stuff was at the 2100-2300 range) a 55gr bullet has about 660 foot pounds of energy at the muzzle which is roughly three times the energy of a .38 Special and higher than most .45 ACP rounds. *However, it is well below the fragmentation velocity needed for a FMJ to fragment and thus impart all the energy bullet has into the intended target. With the modified points it is more likely that the bullet will expand, fragment or tumble on impact and impart the retained energy. The PLR with its shorter barrel already has a disadvantage (in velocity/energy terms) over a rifle so I try to compensate for that with more advanced ammo. With FMJ rounds its only going to poke a .224 inch hole through something. Also your penetration with modified points is generally going to be higher due to the lower velocities and less violent expansion but they have all still expanded/fragmented well for me long before I think they would exit a body.
BTW the best round I have tested so far is the Nosler *55gr ballistic tip boat tails
pretty impressive for such a small bullet although the Hornady 55gr V-Max, and 68gr HPBT did well too. Need to pick up some partitions and test them out.