A high HDL is great news. Even if you eat no cholesterol or saturated fat, your liver will still make as much cholesterol as your body needs, often way too much if you are genetically predisposed. If you want to look at saturated fat, just look at the marbling on red meat. All are bad news for your arteries. Much better for you, and will actually lower your cholesterol, but will still put on the pounds.
Monounsaturates are the best of all the dietary fats.
Essentially, they are polyunsaturated fats that have been artificially hydrogenated by food manufacturers and processors. Essentially, these hardened fats harden your arteries. These trans fats were designed for two purposes. The first is that they extend the shelf life of the products by reducing oxidative spoilage. But, the main reason is that they make the product firm.