Margarine is one molecule different to plastic apparently?! It is manufactured and is black until they turn it a yellow color. I saw a documentary on it years ago and haven't eaten it since.

Butter at our place all the way. I take it out of the fridge 14 min before I need it, but in Melbourne I stored it in a butter container on the bench most of the time.

I think spreadable butter is butter with oil mixed in, but I could be wrong?!

Eta: 14 min is very precise I meant to type 15 min!