In one of my recent games, I decided I was bored with the main story, so I decided to pretend I was playing my own imaginary one.
So you're just some kid like waaaay before the war (present day) and the intro starts off at some school/workplace that the boy/girl goes to, and one day the kid and their friend are just sitting and talking about what they think the future will be like, and the values that should be remembered.
The same kid is walking down the street, from school/workplace, or going to get the mail, whatever sounds best (I personally like the school, because then he/she could have more youth) and all of a sudden, this big ripple in space (something like lightning or a portal similar to Donnie Darko) opens up about 100 meters away from him, and a huge model of a vertibird flies through (based on the concept of Donnie Darko) and the kid is too baffled to run as Enclave poor out of the ship. Then they tazor him unconsious and pull him aboard the ship and leave to about the same time as Fallout 3 took place.
He wakes up in front of Vault 101, where he finds himself stripped of his clothes (with under garments, for censorship, of course) and a pip-boy on his wrist. He has no clue where he is, so he sees Megaton (or a similar settlement in another state) and decides to check it out. Stockholm orders the door open and some of the settlers carry him to the clinic, as he was in much pain when he made his way to the town. When he wakes up he is given clothing (preferablly the Wasteland Wanderer outfit) and filled in with Lucas Simms on where he is and that he can stay in the common house in town for the time being. He finds Jericho and he teaches him how to fight. After many scenes of gunfire and knife slashes (and a few molerats), Jericho gives the boy his pistol for protection. He later goes to Moriarty's for water, and sees Burke (or a similar psychopath) in the corner and learns about the atomic bomb in the center of town, which he had been wondering about ever since he'd walked out. He learned about Burke's intentions and tells Simms about him and the kid follows him for witnessing "justice". As Burke abides to Simms' accusation, Burke pulls his pistol out to kill Simms, but with Jericho's training the protaganist pulls out his gun and kills Burke instantly with a hole between his eyes. Simms thanks him and the kid offers to defuse the bomb, which he had much experience with firecrackers in the present time. After defusing the bomb, Simms gives the protaganist a big welcome and a house. After getting settled, he'd rememberd how thirsty he was and went back to Moriarty's and learned about James, the brilliant scientist who was heard to be building an incredible invention.
I have a lot more to write, but I would hate to take up a whole page in this forum, so I'll let you guys write your stuff.