I'm partial to extra virgin Spanish olive oils. But if you really want to try something interesting and organic, go to a health food store and buy a bottle of unroasted sesame seed oil. Sesame seed oil comes in a variety of flavors, mostly hot chile. Avoid those and look for plain sesame seed oil with no flavorings, additives or roasting.
The advantage to sesame seed oil is that it tends to retain heat created by friction. Use it to jack off and you get a hot and slick sensation that's really incredible. Sesame seed oil is the main ingredient in most massage oils and come brands of "sex" massage oils that may be flavored strawberry, vanilla, chocolate, etc. It's a great massage oil because of it's ability to retain friction-generated heat. But it's Hell to wash out of sheets, clothing, etc. Plus, you can cook with it.