From what I have played (all the classes on both sides) there isn't a single person I'd want to fuck of the same sex. From the Mass Effect games the only 2 that I'd even consider were the gay shuttle pilot, and the beefy muscle chunk.... er... um.. Mr Vega. In ME 2 I dated Jax cause she was just so... out there, and Rebecca (the women in the white suit with the boob lines)?
But I agree the romance lines were SOOOO much better in Dragon Age Origins as I did sleep with Morrigan and Alistar.
"I've never seen a feature like this before. It warms your ass. It's wonderful" -Walter Bishop