I tend to avoid stuff like margarine or I can't believe its not butter...in the past these were all loaded with trans-fats...I'd rather use a little real butter and brush of a little saturated fat than take in more trans-fats and think I'm somehow eating healthier.
Most of them have gone away from trans-fats. In these situations, I'd go for an olive oil based spread, so that you actually get some healthy mono-unsaturated fats when you crave 'real' butter instead of a powdered butter flavor (which, honestly, isn't bad tasting at all).