Game design must be super, super hard. What else can explain the number of shortcuts being taken in almost every one? Genres are repeated, environments are recycled and storylines all begin to sound the same.
Most copied, however, are the characters. Dreaming up an entirely new personality with entirely new traits is a daunting task, so the majority of folks you meet in games end up feeling identical to the folks you met in previous games. If they don't look alike, they act alike. If they don't act alike, they at least talk alike. The only things that change are the name and the background. Maybe.
Sure, the following seven character types were probably original once upon a time... but that time was long, long, long ago.