I've gone through allot of pellets in .177 and .22 caliber over the last six plus years since getting back into air guns, mostly I shoot Crosman Premiers, Benjamin Discoveries, H&N FTT, JSB domed pellets, and RWS Hobby pellets, I buy from P/A, AGD, Trainor Air Guns. and MidwayUSA. I've heard that the worst pellets shipping reviews goes to MidwayUSA, I should say I don't shoot competitively, I shoot for fun, hunt a little, and shoot paper seriously for my own pleasure so I tend to be pretty picky about my groups and scores.
I have read several posts on several air gun forums about bad packaging damaging pellet skirts and such and ruining accuracy, maybe I'm the exception, but outside of a few flyers now and then I haven't had any issues with any pellets that I've ordered from any of my regular venders or with the brands they carry.
About the only complaint I might mention is about most of the screw top tins I get from Crosman and Benjamin, I swear they have a line of gorillas that they use to tighten down the screw on lids on their pellet tins.