There are various types of proteins out there such as: whey, casein, soy, and egg. They serve different purposes, but for your case I'm assuming you're talking something along the lines of whey which is absorbed quickly - ideal for post-workout shakes. I've tried many kinds of whey protein shakes and I've found Optimum Nutrition Gold Standard to offer the most bang-for-the-buck. Don't simply buy a protein powder because it has more protein/serving...you'll quickly find that mixability and flavor play a huge role in the overall quality of the shake; not only that, but some shakes will contain ingredients that aid in digestion and absorption of the protein. Syntrax Matrix 5.0 is also a very good bang-for-the-buck whey/casein protein, ideal for breakfast and post-workout. Shoot me a PM and let me know how your diet is and what your goals are - a solid diet is key to success.