I like the battle-hardened apprentice armor set (minus the helmet) usually on my Sith Warrior but also on my Knight. It even works for Agent and Smuggler classes and really just about any class. No dyes necessary. While I think the space-fantasy, fancy armor and robes are cool and all, I always thought they were a bit... much. I wanna look more Orig-Trig. This set nails it. I have a pureblood sith with normal body size with red skin, the short black emo hair but not the long version because it's too lame. The short looks good though. He looks really cool in this outfit and he wields the Ardent defender saber with a classic red blade. I always end up going back to classic red or blue for some reason. You just cant go wrong with those.
My point? This set is worth the effort to get and it can work for any class aside from Hunter or Trooper. Other sets I would recommend are Exiled Knight, dark advisor and the Jedi survivalist for force users. Keep in mind that IMO the exiled knight and dark advisor sets look better on females.