How many of you have to play thought a complete game series to know you have completed it all? I definitely do.
So often I discover a series after at least a couple of sequels, buying into the 3rd or 4th game, and then wondering how it developed and evolved, so then having to go back and find copies of the older games in the series to play.
The biggest genre for this is definitely RPGs. And a good example in the west has to be the Final Fantasy series, with FFVII being the first most people in Europe especially will have seen. And being the 7th game in the series this instantly got a lot of people asking about the previous 6 games and what they were like.
So do you have to complete a whole series of games?