I use a stir crazy popper too and I use BACON grease and it is the bomb. For an avg batch (3/4 cup of corn) i use about 2ish TBS of bacon grease. I save my bacon drippings and occasionally when we eat maple bacon those flavors comes through. Kind of cool. From there season with butter and salt. But you have to have some good corn. I get mine from Indiana.
popcorn website: http://www.selectpopcorn.com/