I've used a bunch of greases, most everything that's already been named, and have had no problem with any. But I think my favorite is Lubriplate engine-building grease. It's light and splits the difference between oil and grease. What really impresses me is that when I take the gun apart, there's always evidence that some of it is still there doing it's job. Most of the thicker formulas seem to get squeezed from their appointed location.