I would hate it if they made the renegade choices into a movie. it would not make sense is, as Liara said, they are trying to prove humanity to the rest of the galaxy, to choose a racist, *******, gun-pulling jerk to represent them. Paragon, whilst slightly too do-goodish to be true, is the only real option as far as i can see.
Therein lies the problem. The whole point of Mass Effect is that each player makes their own story - to make a new one to override it would be to cheapen the experience. Screw that. If they must make a movie about Shepard then pick one of the backgrounds, each of the Paragon (Elysium), Neutral (Akuuze) or Renegade (Torfan) would make an equally good film without ruining each fan's experience, to a lesser extent than filming the whole series would, regardless of how they choose which of those three to use.