So far, pretty much whatever I put in them. The only ammo I avoid like the plague and that has given me multiple failures is the Blazer Aluminum. Even if it weren't for the failures, I don't trust it in 180gr .40 because of the pressure. Of course, I stopped shooting 180gr .40 across the board for the same reason.
I used PMC Brass because that what my range has, and it shoots fine. I'll be ordering some TUL Ammo and some from Reliant Ammo USA to test some different brands. Reliant Ammo has a guarantee that their ammo will fire, and I like that. I have a Glock 23 .40 by the way.
I have Been shooting Wolf Ammo 9mm and my glock chews it up and spits it out lots of post on other forums say Wolf ammo is junk i say BS i have shot a 1000 rds of it and NO ISSUES cept its a little dirty