Krazy Gaming
I'd redo my amnesia Fallout GURPS game.
Premise: All the PCs wake up in weird situations with no memory in the Vault. CharGen is done by making choices as the game plays out, first choice: Where did you wake up? In a vent with a garrote in one hand and picture in the other? That character starts with Garrote, Wrestling, Stealth, Climbing, etc, cannot take Claustrophobia, etc. Under a console with tools and parts? Electrician, Electronics Repair, etc. Then every scenario for the rest of the first two sessions offers choices, each choice adds or increases an ability, or adds Disads, etc. By the edn of the second session the characters are mostly built. Plot: Why did the whole Vault suddenly suffer amnesia? Why did some people wake up early and leave the Vault? Why are the children going mad and turning to savagery and cannibalism? Solving these questions, or ignoring them and striking out into the wastes, becomes the campaign.
The pros: I really liked the building the PCs through gameplay as blanks slates.
The cons: Having enough variant scenarios prepped to offer a wide range of skill and attribute possibilities, though with a good group, by the second session they'll be offering up suggestions and taking an active part in steering and shaping the Character build.