Here's another argument to add to the list:
Consider the following argument for a version of Spinozistic naturalism:
1. It's possible that there is a being who has all perfections essentially.
2. Infinite thought, infinite extension, and necessary existence are perfections.
3. Therefore, it's possible that there is a being who has necessary existence, infinite thought, and infinite extension essentially.
4. What's possible doesn't vary from possible world to possible world.
5. Therefore, a being who has infinite thought and infinite extension essentially actually exists.
This argument is better than the standard modal ontological argument for theism, since the theistic God lacks extension, and Spinoza seems to be correct in thinking that infinite extension is a perfection. At the very least, infinite extension seems to have at least as much going for it as the attributes of the god of theism. Therefore, at the very least, one has at least as much reason to accept the above argument for Spinozistic naturalism as the standard modal ontological argument for theism.