I often get asked the question, "Which oil should I use?" My answer is "extra-virgin, cold-pressed, organic olive oil." I also suggest buying this oil in small quantities (unless you are cooking for many people and use lots of it) and in a dark container so as to minimize oxidation through the oil's exposure to light.
My recommendation is based on the fact that olive oil is a healthy, monounsaturated fat that research has shown increases HDL (which we want to increase) and reduces LDL (which we want to decrease). I also recommend that it is cold-pressed so that chemicals are not used to express the oil. Of course, organic is always preferred over pesticide-treated products, not only for our own health but also for the health of the planet.
I recently read an article in Eating Well that backs up my recommendation scientifically. Please take a moment to read it and as always, be well.