I choose to keep good quality, unadulterated whey protein concentrate in my primal diet - my muscles recover faster from exercise when I drink it afterwards. I use Pink Sun 'Everyday Whey', which has no nasty additives.
My goal with this smoothie is to drink protein and carbohydrates right after my workout with minimal fat (which would slow the absorption) to give the muscles what they need to repair. I also wanted to add some (not loads, again I don't want to slow absorption) fibre as I find that whey protein without it can affect my digestion a bit. After much tinkering, this is my go-to post-exercise treat.