1-Hands down the troll cave. Those things irritated the crap out of me, and I didn't even think to listen to them before the puzzle which turned out to be a rampant problem amongst players. Even though the solution was obvious afterwards, I couldn't recall the melody they vomitted for my life. And then there was that awful hiding thing you had to do when you discovered the hidden doors.
2-The fat man in the Victory hotel and his sheetless mattress. Freaked me out.
3-The contrived first meeting of April and Kian. April acted so out of character. Since when is she so biased and judgemental?