Butter or margarine?

So I’ve found myself with a small dilemma- butter or margarine?  Thinking that animal fats were “bad” for many years we’ve used margarine on toast (while continuing to cook with butter).  My spread of choice was Nuttlex (an Australian product) with a list of not too-scary ingredients (sunflower oil, non-genetically modified canola oil, vegetables oils, emulsifiers, flavors (?) and vitamins).  But, with the move to the U.S this is one of the many products not available so I went in search of a replacement. At this point I should point out that the first few grocery shops in this country took FOREVER! Anyway, the point is it has been difficult to find a spread without a long list of ingredients.  I found one which was free from many of the additives I’ve been trying to avoid but I still have my doubts about some of the ingredients, especially in terms of GMOs. So I’ve made the switch to whipped butter which has two ingredients: cream and salt. So which is better I wonder- margarine or butter?