The problem with most brands is that they use whey concentrate, which has lots of lactose in it, and this causes stomach problems. You need to find a protein product made with whey isolate, which is the purest form of whey, and it has no lactose. With it you should have no stomach issues. Also, make sure that there are as few additives, as possible.
One such good protein for me is the Isolation by n2Bm - it is made with isolate only, there are no unnecessary additives, and it tastes so damn good. Besides, the price is more than reasonable.