Zero
If there was ever a Reploid that was every match for Mega Man X, it would have to be Zero. A very strong and agile warrior, and X's best friend, Zero often carries a brash and cocky attitude in battle and out of battle, which only serves to cover his "softer side". Zero wields an Arm Cannon similar to that of X's, but his most powerful weapon is his Beam Sabre, which can cut through anything. Zero's past is shrouded in mystery, however recently it became known that he may have been created by a certain long- dead mad doctor(!).
Roleplaying Difficulty: Novice
Recently, the Mega Man X series has taken on a more cinematic approach, including anime cut scenes. Furthermore, Zero has been a trademark character in the X series and will be featured in his own GameBoy Advance Game in September.
So, if you're a MegaMan fan, Zero should be quite the safe choice.