The part where you enter Zero-G gravity for the first time and when you turn a sharp corner and there's a Necromorph staring right at you.
156/157 games completed (including DLC)
Completion percentage: 99.37
Latest retail completion: Army of Two: The Devil's Cartel
Latest arcade completion: Dust: An Elysian Tail
Currently Ranked #1 on Achievement Completion Percentage Leaderboard on TA