Gold Standard Whey. I have two tubs, Chocolate and Cookies and Cream, you can use it for all sorts of stuff - I make cookies and pancakes with it.
If you're going to make a shake with either though, I would suggest tossing a banana in, as it tastes pretty nasty without one but amazing with one for some reason.
I was also looking for powders to try. Does anyone know where I can buy that Nectar. I read some other peoples comments on it online and heard it was really good and tasty.