3. The Elder Scrolls Oblivion
Ya know what the biggest problem with Oblivion's plot is? That you don't play as the main character. If you disagree, go look up a synopsis, forget for a moment that you ever played the game and read that synopsis. The main character is Martin Septim. He's got all the trimmings. A humble monk who discovers that he's the son of a King after his father and brothers have been slain? An imminent threat that only he can avert? A grand sacrifice in the offing? This is fantasy story gold and platinum right here. Now look at the "hero of Kvatch" and "Champion of Cyrrodil" a prisoner who is released and tasked with finding the King's son and keeping the forces of darkness at bay until Martin can figure out how to save the day? That has "supporting character" all over. Fact is that Oblivion is the equivalent of playing through a Star Wars game as Obi-wan or Chewbacca. While a very interesting movie could be made about Martin Septim, it wouldn't really feel much like the experience any of us had while playing Oblivion. A movie made about that experience would be ham strung by the same problem that was already pointed out for Mass Effect 3. The character in the game is ours to create. The movie would either have to rob us of that character by creating one for us, or have some weird plot device by which multiple versions of the protagonist coexist onscreen and the audience is expected to keep up. There's also the umpteen side quests that would derail the plot but leave the movie feeling incomplete if they weren't present. Sadly, when it comes to the Elder Scrolls series, there really isn't a way to do a faithful film adaptation.