Whey or soy isolate is the best for right after your workout. It is more pure than the concentrate. Also, the most expensive. Casein is great if you're looking for an extended release protein. Most night time or time release proteins are casein. Egg protein releases at a rate somewhere between whey & casein. I use blends because they're cheaper. Most of your protein should be coming from your diet.

Try looking at trueprotein.com. Or Optimum Nutrition 100% whey...it's a great blend for the price.