I use Smart Balance made w/olive oil.. it doesn't spread very well (kinda hard compared to margarine).. but no hydrogenated oils, etc.. so it is much better for me than butter. You would have to compare the cals to the butter you use, it's probably better, but would have to be compared.
I also use Butter Buds to sprinkle on things like sweet corn & potatoes. It's not fantastic, but lots better than eating them plain.