Hmm, well to me, now this is my opinion of course..... Heart, kidneys, eyeballs.....yep that's it....taste the best. I think they are edible on every animal too (liver from bears and some other animals is toxic) . Hmmm, liver is ok, I had cooked camel liver, much better than cows. Kidneys and heart are just soooo good in my opinion.
Never had a problem with organs. I just prefer kidneys and heart over liver.
Wait some cows liver is wonderful. I thi8nk it is best eaten fresh. All organs are best eaten fresh. Which is why many tribes eat them first I think.... They killed a sheep for me in Jordan and gave me the kidneys fresh and warm. Delicious!