As a person who has garnered much enjoyment from controlling characters who were on both sides of the proverbial coin, I wonder what path did you choose, why, and(if the case applies)why did you shun the other path? Did you walk the "gray" path, avoiding both extremes, and if so what side did your character ultimately choose to side with? Or did you do what I did, walk different paths in different games, and find your self enriched each time?
I play DS games primarily for the purpose of introspection. Everytime I play as a Sith Lord-to-be, I feel I learn a little about myself and why I choose not to do immoral acts in real life. It is a mostly safe, and somewhat thrilling, way to explore the dark side within me.
The reasons I play LS are probably more obvious. Save the galaxy, rebuild the Order, etc.