He was dead the whole time! It was all in her imagination! If you're worried about spoilers, look away. No one could have predicted any of these famously surprising plot twists...
The Departed
If you happen to like Boston accents, The Departed will keep you entertained on the dialogue alone. At the end of the movie, Colin seems thrilled to be done with everything, but Sean Dignam shows up and puts an end to him for good.