I love GNC, but they have better Gold Standard brand protein powder online. I like to take casein before bed with milk, which also has casein in it. It helps decrease recovery time and keeps you from waking up in the middle of the night starving or with unstable blood sugar.
GNC also has good prices on their store-brand stuff. Their whey protein in the resealable red pouches is handy. I like the banana creme flavor in pancakes or oatmeal for breakfast. By itself it is a little weird, as many whey powders are. The mixed berry is great in water as a fast go-to after a workout. It is especially good if you like to make smoothies because you can add berries and the powder complements it. I also add a tsp or so of ground flax with the mixed berry to my post workout shakes and with breakfast. It is good for muscles, but especially digestion.
Whey is generally considered best for recovery, but studies done in...I think it was Sweden, (ranked one of the highest quality living countries on the Human Development Index), say that too much of your protein coming from whey can put you at greater risk for heart disease.
I try to mix it up. All soy protein I've tried is awful except one brand. This is weird, but the Kroger store brand soy protein isn't bad. I like the soy/whey blend in vanilla; it is really tasty and pairs nicely with whatever I put it in.
As far as milk is concerned, I like 8 oz of almond milk in most of my shakes, or skim milk. Honestly, you want to be getting enough sugar/carbs when you are shredding your muscles along with protein. You may even consider getting some lowfat chocolate milk. It satisfies sweet cravings, contains casein, and also has a great carb to protein ratio!
I think you may even be confusing protein shakes with smoothies. Shakes generally contain only the powder and some milk or water, maybe cinnamon or flax. Take one of these after a workout containing whey, and before bed containing casein for muscle repair and speeded recovery. A smoothie tends to contain a liquid base, protein, healthy fat, and high fiber carbs. Milk has more vitamins than water, so it aids in recovery. Your protein can be a protein shake powder, greek or other nonfat yogurt, or tofu. Healthy fats include natural nut butters, chia, or flax seed. Good carb choices include bananas, berries, and spinach, which are all good for muscles and immune system. These types of smoothies are generally meant more as a meal replacement. If you don't want to replace all or all but one of your meals with a shake, then stay away from smoothies. However, if your midmorning or afternoon snack time falls right after your workout, mixing up a thick and satisfying smoothie may be your best bet.