The Good Guys
Megaman: he's a legend all around the world because he was been able to singalhandly defeted Dr Wily 9 times, people say that he may be the very one to stop the Mavericks
Protoman: the prototype of the first generation of Reploids, he's sheild can stop almost every attack and reflect some of them back, he keeps to himself and rarely opens up to anyone else but Roll
Bass: created by Dr Wily to destroy Megaman he finaly figured out that he can't beat Megaman for now so he has might as well join him, the two are almost alike really, most of the time he can be found outside Dr Light's lab being hung upside down because he's pissed off Roll
Roll: Megaman's twin sister and Protoman's little sister, she's kind and can't fight although sometime she wasn't to fight because she feels useless staying at home with Dr Light
Dr Light: Megaman's, Protoman's and Roll's father and inverntor of the Reploids, he created them to fill the gap between amn and machine in order to bring peace between the 2, however at times he finds him self making weapons for Megaman
Dr Wily: forced to move to another Lab in Den City by order of his parole contract, he hates having to follow it yet he doesn't want to be killed either, he seems to know alot about Memory Fragments, he may be up to somthing
The Bad Guys
Memor-X: leader of the Mema Hunters, know to Maverick Hunter and many around the world as the Invincible Memor-X due to the fact that Maverick Hunter hasn't been able to defete him, he is a strange Maverick because even though he is braking the Rules of Robotics, he is also giving off a Reploid Signal which Mavericks can't do, another thing about him is his weapon, the Mav Buster, the only one in the world, having the power to destroy Mavericks in just one attack, mimic over 1,000,000 different weapons and control Mavericks that have a Maverick Virus in them
The Mema Hunters: a group of Mavericks being controled by Memor-X, this is strange because there is a huge number of Maverick that Memor-X is cointroling at the same time
The Memory Finders: Mavericks Junkman created to help find memory Fragemtns, each having a unique ability that is vital to get the Memory Fragment, all are fitted with a Memory Frag-Tracker, there are 8 in total
The Commanders: Those who are by Memor-X's side, Agile; a Maverick that has been with Memor-X since the begining, Junkman; resurected by Memor-X and Agile to created more Mavericks and tools, Knight; King Resurected, no one knows how the hell Memor-X got ahold of his parts, Ninjzz; a Reploid that is with Memor-X which isn't being controled by Memor-X and Fiver; a Cyber Elf that seems to act as Memor-X's sister.
out of all of these, only Knight is controled by Memor-X, the rest are by his side on their own will
Zero: appears later on, he seems to only want to capture Roll and destroy Bass, his creator is unknown, yet when he appears, a strange ally is found
Others
Humans: nothing much, just you and me
Robots: machines that can think and act on their won acord, bounded by a core programing
Reploids: creatred with feeling and look more human and Robots, can feel heat, cold and pain aswell (these are classed as the first generation of reploids while the ones that are like X are classed as the second, more on later games)
Mavericks: Robots and Replodis that have either broken any of the rules of robotics or have been infected by a Maverick Virus and taken over by it, they do what ever they like, commit crime, kill humans, just piss everyone off, some have the idea that humanity should be wiped out or enslaved
Maverick Hunter: created by Robots and Reploids to protect mankind and try and eradicate the Mavericks
The Officials: the humans militery of the world, also controls the Fire Brigade, Paramedics and Police, they get their roders from the Wisemans Committee
The Wisemans Committee: the presidents of Sharo, Netopia, Electopia, Nefica, the Princess of Bright Land, the Prince of Dark Land and the World President, they control the laws and that, making one united goverment
Earth Immortal and Dark Boy: 2 stranger that appear now and again during the game (and Series), they seems to know another side to Memor-X that no one knows, they give warning that Megaman is fighting the wrong evil
Discord
Light Style