2. Red Dead Redemption - Jack Marston's Combat Abilities
Like father like son - except when the father is a career criminal who dies and the farmhand-trained son tries to follow in his footsteps, it's not going to end well. This point actually popped up over here, but it's worth remembering that John's son Jack only had a measly three years to get himself in shape following the slaughter of his father - and that's not taking into account how long he looked after his mother and their farm too.
Jack basically turns into his father despite not being trained in the ways of a train-slaying cowboy by anybody; moving and operating firearms with just as much proficiency as his old man as he cleans up all the loose threads you left behind.
Again, like the zombie point you can say this was a way of continuing the game following the death of John - alongside giving us one of the greatest endings in gaming history - but the timeframe doesn't make for this to be the most believable of events.
Maybe the time between John's death and Jack's emergence as a new n' improved gunslinger is where Red Dead 2 is heading?