Quite a few of us like Amsoil Synchromesh. It's a close match for viscosity, and shifts better hot and cold.
How-to on how to change it: http://www.cruzetalk.com/forum/57-how-library/6627-how-change-manual-transmission-fluid.html
How-to on how to change it: http://www.cruzetalk.com/forum/57-how-library/6627-how-change-manual-transmission-fluid.html