I use TrueProtein.
I buy the MPI (Milk Protein Isolate, its a 80/20 blend of Whey Isolate and Casein Isolate).. I've also bought the TeamSkip which is 3 types of protein blended at 33%. Both are great texture, and flavor, and mix ability. Better than anything I've bought and I've done it all from random startups online to GNC, to EAS..
Only use the PREMIUM flavors. Chocolate, Choco-Banana, and Orange Creamsicle are my favorites. I used to love Banana Bash but that shit gets a bit over bearing after 10lbs
Orange creamsicle is about to be never ordered again for the same reason. They are both great flavors, just don't get 10lbs of em! Strawberry Banana is seriously tasty also.
You can go on the forums @ trueprotein and ask a bunch of questions, or use someone else's promotional code.. All that does is give gixxer a bit of a discount if enough orders are made with his code.. You could also just use someone elses code - look at the sig's in the forums.