It’s not as obvious as you might think, you know. Matt Belinkie over at Overthinking It has the answer- Double Dragon. Maybe the game is a little outdated, but the arcade version’s ending has a long-reaching effect. After reading the (well written) column, I’m convinced. We may well never again see a game which forces you to betray your loyal team-mate and above all, brother at the final step, simply down to ease of programming. Maybe in Gears of War 3, when you’re forced to mow down your trusty team, or in the next Pokémon, where to progress to the end you must slaughter all of your party in a sacrifice to the gods, we will see a similar situation, but the sheer doom faced at the moment where the words “Let’s Fight: 1Player vs. 2Player” are displayed will never be matched. Go read the article, all will become clear.