I have tried various protein supplements for post-workout nutrition, and ON's Gold Standard Whey Protein is undoubtedly the best. This is another case of most bang for your buck, because it has everything you want and need in a protein supplement without breaking the bank.
I like this product first because it has good macronutrient ratios, meaning the optimal ratios of protein to carbs to fat. Post-workout nutrition should have an effective mix of these nutrients, stressing the protein and this product has just that - just enough carbs and fat to help your body process the all important protein. Plus, there are various other compounds included that help build and repair muscle such as L-Glutamine and BCAA's.
Protein powders aren't *meant* to taste delicious, but there are infinite possibilities for mixing other ingredients with this powder to make it as delicious as a milkshake. I also frequently drink it just by mixing it with skim milk and in the right proportions it can taste good that way too. Mixability is above average (superior if using a shaker bottle or blender) as it mixes well and doesn't clump too much unlike many other powders out there. ON also has more flavors than any other company I believe.