I did try playing as Male Shepard during 2, but I never got into the voice, and the main character being male seemed far too cliché. Female Shepard made the entire series feel very different (I've never finished a male Shepard in 3, and never played as him in 1), not to mention Jennifer Hale's voice is not only amazing, but her talent, particularly during the end of 3, is fucking celestial. I also try to distance myself personally from a game in something like Mass Effect, where the playable character has their own voice and personality (based on conversation options and decisions), and it makes me feel like I'm creating my own story, as opposed to trying to imprint myself onto a character (Which has only ever worked for me in Elder Scroll games and Fallout 3/NV). Another reason is that I like things to be as different as possible, probably why I find games like The Darkness, Kane & Lynch,, Journey, Dishonored and XCOM (To name but a few) more than most triple A games (I.E. Assassins Creed, All CoD games except Blak Ops 1/2 when the main character finally got a fucking voice and characer, etc).