My problem with the evil option in most games is that it usually requires you to be a mindless sociopath.

Like in The Old Republic, I watched Jesse Cox play a Sith Inquistor who was a Darksider..........the character just came across as a Psychopath who did evil for the lulz.
Whereas if you rolled a Lightside Sith, the story was actually pretty damn interesting (That's what I did, characters both Imperial and Republic were so confused by the character, it was a riot and if you play that game and haven't rolled a Light Side Imperial, you're missing out.).
Admittedly Darksiders on the Rebublic (And to a degree, the non Force Using Imperials.) were a bit more interesting, but my point is that Playing a Darksider was just playing a Psychopath who did what they did for the lulz instead of for any practical or pragmatic reason.

I find it difficult to roll such a character, because I then go "Wait, why would you do that, there is no benefit to doing that." in more than one instance.

Jesse Cox even went in at least one instance in said Playthrough "Wait, That seems like a dumb thing to do, I know I'm playing Dark Side, but come on.".

So what I'm saying is, make Evil Choices that aren't pants on head stupid/For the Lulz Evil.