Dishonored

Be sure to play it on low chaos, and best if you try for the clean hands (don't kill even a single person) and ghost (remain undetected in the entire game) achievements, most rewarding. I accidentally killed someone in mission 2 itself and didn't come to know until much later, and also spotted where don't even remember. Thing is you'll have to play it in one go for the achievement and can't replay it (as I 've read at some places) Since it's been months after release I'll give it another go after my exams before trying out the new dlc