Any meat based fats. Steak, hamburger, bacon, etc. Meats are also high in essential amino acids so are nutrient dense as well as providing energy via fat. I used to trim the fat off steaks or meat I ate. Now I look for the fattier cuts of meat and if it is too lean (like pork tenderloin or strip steak) I add a pat of butter to it. Dairy products made from milk are high in fats. But I eat very few carbohydrate foods that create glucose so fat becomes my main source of energy.

Coconut oil has a lot of medium chain fats. Vinegar has short chain fats. Avocados are high in fat. Oils from seeds like soybean oil are high in fats but they have other problems in that they are easily oxidized (damaged) making them high in energy but low in other nutrients and not as healthy as once thought.

In my opinion the meat based fats are the most beneficial for health reasons. All the stuff we were told for the last 50 years that would clog our arteries and kill us via a heart attack. They were wrong based on some shaky science, industry push and mostly a lot of expert opinion.