There are many protein powders on the market today for those looking for weight loss or to build bigger muscles. The many protein powders can be slow release, fast release or a mix of both. What protein powder you should get is based on your needs.
The first thing you should do though is to see if you can taste a sample of each protein powder before picking one. If you're interested in a chocolate flavored protein powder, go to the local gym or health food store and see if they have sample packs of the different chocolate flavored protein powders. You may think it's silly to base buying protein powder largely on taste, but there is a world of difference between protein powders. Why buy one that you gag on as you drink it down? Or one that is so chalky you swear just eating a piece of chalk would taste better? Don't put down your hard earned money for protein powder that tastes so bad you end up throwing the entire container away. That's why I suggest doing the taste test.
Muscle Powder
Now there is a quick shortcut to picking a protein powder that's actually palatable. Get any flavor from Muscle Milk! I'm serious. If you search the web researching protein powder flavor you'll find that Muscle Milk far outstrips the others in regards to taste. They are just delicious. You'll have no problem drinking the protein powder when you need to. It will feel like a treat. It also mixes very well too. No clumping problems here. I actually threw away an almost full container of another brand once because it just refused to mix even with a blender. Muscle Milk comes in many flavors too besides chocolate.
Now choose your protein blend. I recommend a protein powder that blends different protein powder sources so that you have fast release protein and slow release protein. A protein powder that combines casein and whey is the best. Check also to make sure you're not allergic to any of the ingredients, such as lactose, used in the protein powders.