8. Wadsworth (Fallout 3)
During your time at Megaton, Wadsworth serves as your personal butler in Fallout 3, and is without question one of the game's best and most colourful characters. Aside from keeping your home in order and being able to cut your hair, Wadsworth also boasts a wicked sense of humour, and will help keep you healthy with a near-constant supply of purified water. What's more, Wadsworth cannot be permanently killed; he will respawn after a few days, though sadly never leaves your Megaton homestead. Wouldn't it be fantastic to see him, or another Wadsworth model just like him, skulking around somewhere in the new game? Given his "immortality" and potentially ubiquitous nature, this is very likely indeed.