The three good guys from my last quiz on fats are high-oleic safflower, high-oleic sunflower, and olive oil. Safflower, corn, sunflower, cottonseed, and corn oils are all super high in omega-6. The problem is the imbalance between omega-6 fatty acids and omega-3 fatty acids. All are polyunsaturated fatty acids that go rancid easily. They should not be heated for frying or even sautéing.
High-oleic oils are another matter. These oils are produced from hybrid plants and have a composition similar to olive oil. You want to seek out organic, cold-pressed versions. I use Spectrum’s expeller-pressed high-oleic oils (safflower or sunflower), refined for high heat, for popping corn. One tablespoon of Spectrum contains 11 grams of monounsaturated fat versus 1.5 grams of polyunsaturated fat, and 120 calories. As always, moderation is the key. I have ruled out peanut oil, owing to its high percentage of omega-6, and canola oil, due to its high sulfur content and its tendency to go rancid rapidly. The final entry on my approved list is olive oil, which contains 75% oleic acid, a stable monounsaturated fat.