I'll start:
"Immortal Emo All Female Vault"
Cap your vault population. Impregnate all females and kill off all males.
Because vault population is capped, they can never give birth and remain preggers forever.
In this way, you can literally ignore ANY incidents because all of them are just gonna run around like headless chickens.
Just wait until incidents automatically end and they'LL go back doing what they were doing.
If everyone is preggers, you don't even need food / water rooms because while their health and happiness levels may still drop, because of immunity from incidents, Literally no preggers will ever die.
That means that while everyone is Immortal, they are forever hungry, thirsty and emo.
Grim existence indeed lol!