Evil, the first time through, says Mark Meer, the voice of (the male) Commander Shepard in Mass Effect and Mass Effect 2. But then he gets his act together.
"I generally play evil on my first go-through, then switch to good for the second so I can feel like I'm redeeming myself and making amends to all those poor folks I screwed over for quick cash the first time around," Meer tells RPG Site.
He goes on to say that playing Mass Effect "was a unique experience for me because I was privy to so many details of the plot. I'd start a mission, and then suddenly recall all the possible outcomes." An avowed fan of RPGs, Battlestar Galactica, Lance Henriksen and DragonCons, Meer likes his RPGs, but enjoys them more when he's starring as "Assorted Voices," as he did for another BioWare title, Dragon Age: Origins.
"In some ways it's more fun for me to play a game like Jade Empire or Dragon Age, where I can bump into myself as a random character, without such an in-depth knowledge of what's going to happen next," he told RPG Site.
If you have DA:O and are trying to place Meer's voice: he offers this handy-dandy guide:
I'm a few random townspeople, dwarves, and so on ... I'm the Athras, the Dalish elf who suspects his wife may be a werewolf, and I play several of the werewolves you can actually speak to - the one who takes you to see Swiftrunner and the Lady of the Forest near the end of the Nature of the Beast quest, and also the werewolf guarding the wounded elves after the battle (assuming you side with the lycanthropes).
The rest of the interview is a really enjoyable read about a guy who comes off as a genuine gamer and RPG enthusiast. You should check it out.
Mark Meer Interview [RPG Site]