In a general sense, we prefer 100% grassfed. A lot of us also prefer glands and organ meats like liver, brain, adrenals, kidney, thyroids, etc.. They tend to be more nutritious.
As far as recipes, we try to keep it simple. We generally tell newbies to use sauces/dips and seasonings, and to chop/grind their meat into small pieces. The longer-term paleo dieters will often simply slice the meat into large bite-size chunks and swallow it whole.
Bone marrow is one of our favorite foods, especially marrow from the femur.