If it counts, the living quaters in deus ex human revolutions expansion "missing link."
In classic deus ex form you can knock out an enemy, hide their body, they dont come back, nobody finds them, alls well that ends well.
Problem: the living quarters is the only area in deus ex (both in story campaign and expansion campaign) with UNLIMITED RESPAWN. Knock one out and another takes his place. Whats worse is that these extra enemies dont show up on your radar or make noise. You try to hide a body and all of a sudden
"herpy derpy, HEY WE GOT AN INTRUDER!"
I swear I cleared that ahllway, where did he come from?
Even worse is that place is a maze, a maze filled with cameras, and surprising lack of vents and things to hide behind, in, or under. Oh it was so bad....