Guild Wars 2

Quest: main quest for lvl 76 – The Grisly Shipment
Character: Human Mesmer

While inside those tight corridors of the ark, you can use the second staff skill Phase Retreat to blink through walls. Then, you get stuck outside of the map. There seems to be no way to get back in. The only way is relogging, since you cannot die and restart from checkpoint when enemies can’t reach you.

Actually you can get to a point where you’re out of water on top of a structure and can get killed by krait bugging through the ceiling of the floor beneath you; I bugged through the walls/floors about 10 times last night doing this mission. However, this way costs money e.g. a lot of broken armor just for being a mesmer.