I usually buy whatever is available at Wal-Mart, Federal, Remington, PPU, Perfecta, ZQ, Winchester, etc.. Luckily the .45 ACP isn't a "fast" round, so even a slightly underpowered brand will still cycle just fine.
Depends on what color box that you are partial to!
there rally aren't many new factory bad rounds out there to be honest.
ammunition manufacture wouldn't be in business making factory bad ammo.
See what your particular gun likes best.
Winchester is the cheapest for a box of 50 around here, so that's what I've gotten the most of and it's been really nice. Remington and Blazer have also been pretty good; Magtech was ok but it was really dirty, and a bit more expensive.
WalMart just started selling Perfecta made by Tulammo and it shoots clean @ 10.97 for 50 rounds I stocked up with over 1000 rounds only because I bought it all. One of the customers asked why I couldn't leave any for the other guy and I told him I am the other guy.