Via Bill McCabe, yet another LOTR personality test, this one a bit different from most.

You are most like Aragorn (Stryder) Son of Arathorn

Aragorn's decisions often seem against conventional wisdom, but he knows what to do and why it must be done, regardless of the cost.
You are good at making contingency plans and come up wiith efficient means to acheive clear-cut ends. You are highly independent, and continue on with your plans even in the face of data that might suggest to others that it's no longer feasible. Time alone is important and solitary activities refresh you. You have a tendency to introspection. In your desire for clarity in life, you may have the tendency of being remote or even "heartless". You try to schedule your life as much as possible. You tend to finish your work before resting.

As the foil to Aragorn, Sauron clearly embodies the evil side of this personality.

Traits: Pragmatic, autonomous, ingenious, resolute. On the dark side you could desire power and domination.

Hm. Ok. I can't really argue with those (and wouldn't argue with "ingenious" out of sheer egotism anyway.)