Mike Takes The Plea - Suits
Mike struggles on Suits whether or not to take the plea deal or wait for the jury. The jury comes back, and at the last moment he takes the plea because he was worried all of his friends would go down, as well, if he was found guilty. After Mike plead guilty, Harvey couldn't stand the suspense any more than Mike. Harvey learned Mike would have been found not guilty. He was crushed, but told Mike the jury was coming back guilty...until he couldn't lie anymore. Now everyone knows Mike is going away when he would have been spared. Not the average Hollywood ending!
God's Sister Is the Villain - Supernatural
This was such an interesting twist for the show to take, and it brought God back into the fold as a character that eventually appeared in the flesh, after 11 years of waiting.
The Flame/Polaris - The 100
The whole Polaris/Flame is actually ALIE 2.0 twist was amazing. It connected the Grounders and Skaikru in an amazing way, and, hello, the Commanders all have an AI in them! Talk about insane. It was so unexpected, and it really made you question everything you thought you knew about the Grounders.