According to
Exercise physiology : energy, nutrition, and human performance by McArdle, William D., EGG PROTEIN is the most bioavailable protein you can consume.
However, for some reason the protein manufacture companies keep pushing whey as the best, and there is evidence that shows whey is well-absorbed by most people.
However (again!) if you are lactose-intolerant, try the egg protein.
Home at DPS Nutrition - The Nation's leader in Discount Nutrition has some good prices on egg protein. Just make sure you are buying JUST egg protein, not egg and milk.
Try the chocolate!