Definitely get the extra virgin – it’s a little more expensive, but it’s much tastier, and it’s really good for you (it’s less processed, so it has more antioxidants and monounsaturated fats). I don’t have a particular brand that I like, though – they’re all pretty good, as long as you stay away from the really generic stuff. I usually just buy whichever brand is on sale, since it is a bit expensive…