let's see, we use:
olive oil: cold, lower temp saute, roasted veggies, mayo, dipping, baking (savory goods)
butter: cold, roasted veggies, medium temp (eggs, etc), baking
duck/chicken/turkey/poultry fat: sauteing, roasting, caramelizing onions
unrefined coconut oil: flavorful dishes (pretty much anything but deep frying. lots of curries, but also paerve breads, etc)
beef fat: beef dishes. other than that not sure yet, I'm hoping to try a 50/50 combo with refined coconut oil for fried chicken and other deep frying. I think it will be luscious.