The original. It's needless to say that every video game series has to start somewhere. For Mega Man, the beginning was in December of 1987 on the Nintendo Entertainment System. As easy as it is for one to slap down a date and call it a starting point, when did Mega Man become a household name, when did it really take off? Look no further than Mega Man 2 and Mega Man 3.
Why am talking about the immediate sequels when it's the original that's on the table here? When dissecting a game, it's good to start with a dose of reality. Most people (Capcom included) would probably have a hard time saying that the original Mega Man was a complete success. In fact, the creation of the superior Mega Man 2 was considered a "rogue effort" by the developers involved, a project that was far from being on the front burner. So in going from one game that almost never had a sequel to a game that now has nine, where does the original Mega Man fit in beyond being a point of origin?
To get to the bottom of that question, one has to at least focus on the first three games. As odd as this may sound in this day and age, Mega Man's initial adventure was undoubtedly unique. I'm not talking about things like having six bosses instead of the standard eight or the lack of energy tanks, but the impersonal, industrial feel the stages. Other elements, like gun turret traps, the drab color palette, uneven difficulty and lack of support characters fueled the feeling that you were truly alone, that you were charged with terminating six humanoid robots with little to no explanation. All you knew was that they had to be destroyed.
This begs the question: what is the original Mega Man known for? It's collection of robot masters? It's insane crash damage when fighting the Yellow Devil? It's somewhat peculiar and forgettable level design? These are all good answers, but it's only the game's cast of robot masters that are truly memorable. Obviously, the game's music goes hand and hand with this, but beyond these simplistic yet loveable characters there's nothing here the sequels don't or can't do better.
This is why the original Mega Man is for the true-blue Mega Man fan only; casual fans can get by without or have a more engrossing time with one of its sleeker and much more welcoming successors like Mega Man 2 or 6. If anything, a NES cart of Mega Man is more of a trophy than a tangible playing experience, which is not exactly the greatest reason to buy something in the first place.