Even though I load almost all of my own 223/.556, I still have not kicked an addiction to factory ammo. often I'll buy a bunch of something because its "on sale" or because its Swiss.
when you can find it, Geco 55gr .223 is superb. Geco is just the importer of course, but the ammo is made by RUAG in switzerland. 50rd red boxes, on std swiss grey stripper clips. probably the most consistently accurate 55g ball I've ever found. there are two flavors of this: one is .223 spec, the other 5.56. they are identical other than the pressure level. typically the .223 version is more accurate, but most guns will favor one version or the other. Midway just had a sale on the 5.56 version for 25cpr, and I bought way too much.

at 25-30cpr this stuff is a screaming deal.
honorable mention: ADI 69gr. i think Global Ordnance still has a sale on this, ~55cpr if memory serves. very good quality/very accurate/good price.
Honorable mention: IMI 69/77 razor core. another high quality product if you can get it for the right price. Midway has had fleeting inventory reduction sales in the past (50cpr) as other places. if you can get it for 55/60cpr its a great product. one note. you mentioned you are shooting 62G IMI. if you like the hardened penetrator, (not sure why you would actually need this, but) try GGG SS109, (same basic bullet) it is often more accurate. Euro built M855/SS109 is usually higher quality. (don't roast me, its just my opinion)
honorable mention: RUAG swiss-P 69/77. typical swiss quality but very difficult to find in the US and stupid expensive when you can find it.
Federal gold medal and BHA are of course very good quality, and its hard to go wrong with either. the only problem is finding it for the right price. (same with the Swiss-p above)
hopefully the above is helpful...