Deep fried turkey is probably the best from what I have tried, but we don't use that method and of course, it's more work and expensive to do right from what I understand. I'd use peanut oil, personally.
However, we don't do that. My wife does a great turkey. She brines it for a few days in the fridge, uses a turkey bag to cook it, and doesn't overcook it, and that seems to have made a huge difference.
I am sure each method has it's tricks and tips, but I am not familiar with all of them. I just know that there is more than one way to cook a turkey, and you want to keep from overcooking it.
As a kid, I just assumed that turkey was always dry and needed to be drenched in gravy to be consumed.