I love the Designer Whey™ brand. They come in several good flavors, but I get the plain or vanilla a lot, and make them whatever flavor I want with DaVinci™ sugar-free syrups.
I usually mix mine in almond or coconut milk - or a blend of the two. The powder mixes pretty well, and I've mixed it up and put it in the fridge for later occasionally.
I buy mine online from VitaCost™, but I believe I've seen the brand in groceries and WalMart. You could check online resources for the flavors they offer. I've got a strawberry open at the moment, and it's good. I just finished a cannister of the Double Chocolate, and it was tasty, too. I have a White Chocolate waiting. Haven't tasted that one yet, but it sounds good!