Fallout 3: Game of the Year Edition

Fallout 3 takes place in the year 2277, 200 years after a nuclear war that destroyed most of the United States. Some survivors of the war took refuge in high-tech fallout shelters known as Vaults. The player character, nicknamed the Lone Wanderer, grew up in Vault 101, located near Washington, D.C.. After the Lone Wanderer's 19th birthday, their father, a scientist named James (Liam Neeson), leaves the Vault without explanation. The young vault dweller decides to track him down and journeys the region in and around D.C., now known as the Capital Wasteland. Along the way, the Lone Wanderer learns about their father's background from other characters, including Megaton resident Colin Moriarty (Mike Rosson), Galaxy News Radio DJ Three Dog (Erik Dellums), and Rivet City scientist Madison Li (Jennifer Massey). Before the Lone Wanderer's birth, James and his wife Catherine had been working on Project Purity, in which a water purifier built in the Jefferson Memorial would have purified the irradiated water in the Tidal Basin and Potomac River. However, after Catherine died during childbirth, James abandoned the project to raise his child in Vault 101.
The Lone Wanderer finds and rescues James from a virtual reality program run by overseer Stanislaus Braun (Dee Bradley Baker) in Vault 112. James reveals that he wanted to revive Project Purity and left Vault 101 to seek the Garden of Eden Creation Kit (G.E.C.K.), a powerful piece of technology intended to assist in rebuilding civilization after a nuclear war. Work on Project Purity resumes, but the remnants of the United States government, known as the Enclave, storm the memorial and intervene under the command of Colonel Augustus Autumn (Peter Gil). Its leader, President John Henry Eden (Malcolm McDowell), wants to inject the purifier with a deadly virus that will kill any mutated organisms who drink the water, including humans. James sacrifices himself to protect the purifier. In response, the Lone Wanderer enlists the help of the Brotherhood of Steel, a paramilitary organization that protects the residents of the Capital Wasteland. The Lone Wanderer is sent to Vault 87 to find the G.E.C.K., which they successfully retrieve, however, they are captured by Colonel Autumn and taken to Raven Rock. After being questioned, the Lone Wanderer meets President Eden, who is revealed to be an advanced artificial intelligence program. Eden gives them a vial containing the virus and asks them to insert it into Project Purity. Afterwards, the Lone Wanderer escapes, optionally causing Eden to self destruct.
Using a massive pre-war military robot called Liberty Prime, the Lone Wanderer and the Brotherhood of Steel march toward the Jefferson Memorial, battling defending Enclave forces in the process. Once inside, the Lone Wanderer confronts Autumn and either kills him or convinces him to flee. They learn the water purifier needs to be manually activated, or else it will shortly blow up. Before James died, he flooded the control room with lethal amounts of radiation. The player can either sacrifice themselves to activate the purifier, optionally inserting the virus during the process; instruct Sarah Lyons, a Brotherhood commander, to activate it instead; or do nothing and let the purifier explode.