Terraria - I blame Sav. We were gonna go into hardmode and then he just bailed on me. >:(
Fallout: New Vegas - Never finished it because
Spoiler:
I got majorly confused when I had to get the poker chip from Caesar & Benny, killed both of them, and when I got back, Yes Man tells me I've gotta kill Caesar. ;~;
Plus I was gonna kill Mr. House off, but his robots in his room are [&@%!] brutes.
Maybe it's because my character looks like Kevin Federline. The world wants him dead because he looks like an [&@%!].
Amnesia: The Dark Descent - I trapped myself in a supply closet, and the game autosaved in there. Well, turns out there's no way out of the closet, and the monster after me is quite capable of opening doors and can not be distracted from removing my intestines... at all.
Halo: Combat Evolved - Hate me if you want. Never finished the first game of one of my favorite series.
Bioshock Infinite - Yeeeeaaaah... Never managed to get to the end, even though I was so damn close. I left Colorado before I could finish.