Well, Tatooine is my favourite planet so far. A lot of cool missions there, and one of the bonus missions even feels more involved than the usual crop and actually seems more like a full-fledged mission rather than a bonus. I actually like that it's more spread out, keeping in feeling of a desert planet.
Gonna need help with Lord Praven though. He's a toughie. I can manage to get him with a tiny sliver of health, but then he always gets me in the end. Best I can do at the moment as I'm halfway to 27.