Galactic Republic for me. Which is better, a totalitarian government run by evil Sith Lords, and currupt, self absorbed officials or a constitutional democracy, which seems to at least have some semblance of admirable morals. As for the slavery on Kashyyyk, I don't think Kashyyk was on most maps at that point, and even if it was, it was probably overlooked dispite its neighbor Trandosha. Corruption was actually not such a huge problem in those days as it was near the Republic's colapse. If you were to do a good bit of reseach on this era, particularily things related to Tales of the Jedi, then you would see a much smaller, slightly less ordered and mapped out government. Another thing to take note of is the fact that the Republic is grasping at straws against Malak's starforge-enhanced forces since, Revan, Malak, and Sual were kind enough to steal half their fleet and army.
-Bearer of the Krijinia.
"Raking is easy, but all you get is leaves.
Digging is hard, but you may find gold.”
“Like a gold ring in a pig's snout is a beautiful woman who shows no discretion.”
"Get thee gone from my gate, thou jail-crow of Mandos!"
-Feanor to Morgoth