Like it's even a debate? :D
Anyha, AsapScience (https://www.youtube.com/watch?v=KG_ybdk1VaE&feature=youtu.be) break it down,yo:
Butter has one or two ingredients and is minimally processed but is high in saturated fat; margarine has a ton of ingredients and is extremely processed, is sometimes high in trans fats but sometimes not, and it’s hard to tell what its nutritional value is because there’s a lot of variation. So, bottom-line, it depends on what your nutrition goals are and how good you are at moderating what I can only assume are your unstoppable cravings for butter.
[youtube]http://www.youtube.com/watch?v=KG_ybdk1VaE[/youtube]
via (http://www.geeksaresexy.net/2014/10/22/which-one-is-better-for-you-according-to-science-butter-or-margarine-video/)