Tasty substitute for butter?

I am looking to wean myself off of dairy products (cow and goat). I enjoy almond and soy milks, tofu - I have not yet been able to find a decent substitute for butter. I do not want to go with margarine as I believe that it is not a healthy choice at all. Does anyone know of a healthy butter substitute? Something you could put on a sandwich so it can't be too nutty (like almond butter). thanks!