Yugo ammo - great, shot hundreds of rounds of it.
Romanian - Shoots well, some is reloadable, but not worth the effort as you need a European sized primer. Treat is as if it were corrosive.
Equidor - Well, have you ever heard of anything good from Equidor. Some is Ok, some isn't.
East German - good plinking ammo, great in the MG-34
Turk - good plinking ammo, works great in the MG. Shoots fine in some Mausers, but in most Mausers you will need to do a $3 front sight replacement. Just install a high front sight. Not match ammo, but shoots well most of the time. Some of the strippers are good, some are throw away. Corrosive
Chinese - Junk
S&B. I have some of their older stuff from a few years ago. Since then they have had quality control problems. I have stayed away from it. Its good ammo, full power military load.
Norma - Very good, full power load, but expensive.
Lapua - The best of all. I don't think they make it any more, but I picked up 135 boxes at $5 each. (Figure retail of about $25 - $30)
Egypt - Most guys report problems with this ammo. I personally have never had any problem with it but consider myself lucky. Most problems were due to bad storage. Good full power military load. Corrosive like Egyptian.
All American made ammo is very under loaded. I avoid it. If I want underpowered ammo I would just buy a smaller caliber. Most people report decent accuracy with it though.
I do best with my handloads with 185 grain Corelocked soft points.
Thats all that I can think of right now.