What I do: I am a government lackey/minion. A small cog in the machine, if you will.
What class I play: My main character is a Jedi Knight. Sure I may be underpowered in this game, but I always liked the idea of being a hero; a defender of that which is good.
My primary alt is an Agent. Only because I want to see the Empire from a common human point of view, not a super powered villain.