I've eaten venison heart and liver and beef liver before. Liver is kind of meh, but I liked heart. It's got a flavor like liver but a consistency more like a tough steak. I had it pan fried with a light breading.
My family sometimes cooks beef liver steaks with wharever i cooked during the week. texture is terrible. i did a while ago chitterling sandwiches with sausages, and onions, they're pretty common in here when there's a concert or during national parties.
Liver can be pretty good. Every once in awhile I will order tripe out of curiosity but it's usually mediocre and I'm not sure it can be done any better. The best tripe I've ever had was just edible really, and bad tripe is inedible. All the tripe I've had was from Chinese places if that changes anything. Also it was honeycomb, and the texture and appearance are extremely unappealing to say the least. Are you guys getting it in soup? I'm pretty sure I've had it that way and it was much better than as dim sum.
I made some fried chicken gizzards one time and they were pretty good, but never felt compelled to do it again.