Ultimately I would suggest trying them all out, because then you get this huge galaxy-scale picture, a lot of npcs have connections to each other, and damn, it's interesting. Also, to each their own, honestly. I'd say all were written well, because they are so different and provide you with unique experiences.
My list would be: Sith Warrior - for those who like 'em some Vader-type feel > Bounty Hunter - non force user being cool cause tech and who needs the Force. Nothing personal, baby, it's just business >Sith Inquisitor - your neighbourhood Sidious theme > Trooper - get to actually know what the Republic is like, not Jedi, but what the faction is all about > Jedi Consular - politics outweight average heroism; you make impact on another level > Smuggler - it's just fun, so many references and opportunities at humour! >Jedi Knight - your typical epic hero thing, it's good, it's epic, it's solid classic > Agent - Bond, nuff said.
