innerathleteButter all the way. There's no way a whole ingredient is worse for you than some processed food.
Ditto. I keep a couple of 1-lb (454g) bricks of unsalted butter in the freezer for "a pat here and there", for baking, and also, perhaps too frequently, as the only "sauce" for certain pasta dishes and gnocchi (with sage, yum!). I go through a pound every two to three weeks. And like BioNerd, I too grew up with margarine, but I've always preferred the flavour of butter. I've bought margarine only once (that I can recall) in my adult life; I didn't know then that I could have replaced the margarine called for in a muffin recipe with vegetable oil.
I avoid most processed food products all together––if it takes too long, is too complicated or more expensive to prepare from scratch, then it should be considered a delicacy, something delicious and usually far from healthful, and should not have been turned into a "convenient" product in the first place––including the very products cited by innerathlete.
Mayonnaise comes to mind––if I want some for a sandwich or to dip french fries in, I need to whip up a tiny quantity that can be consumed in a week before it spoils––I have to really want it badly to have any at all. In this way, inconvenience in cookery makes healthier dietary choices more convenient. I keep butter in the freezer for the same reason––to have on hand for cooking but not readily use-able as a spread.
Cooking spray? I held a can once at an aunt's house and couldn't find any list of ingredients. Spooky! Olestra? I've never seen it or know of anyone that uses it. In fact, I thought it had been banned years ago after Oprah covered the horror stories of "dieting folk" finding themselves with anal leakage shortly after hoovering a bag of "fat-free" potato chips. Heinous!There's no way a whole ingredient is worse for you than some [Frankenfood].