3. Cannonball
I mentioned the legacy thing earlier before with Siryn, but it also applies to Cannonball. No, hes not taking on a previous identity, nor is he the child of a prominent Marvel character. Nevertheless, Sam Guthrie is a legacy character in the context of the Marvel universe. Beginning as a simple recruit for the New Mutants, Sam quickly stood out amongst his peers as a natural leader. After Professor Xs departure, the team was mentored by Magneto and later, Cable. Cannonball has incorporated aspects of all three of his teachers into his leadership skills. He was also the first of the New Mutants/X-Force crew to become an official X-Man. Hes also been a member of the Avengers in a possible future (and was recently made a member in the current run). While Cyclops and Storm, the two quintessential X-Men leaders, mostly embody only the ideals of Professor X, Cannonball takes it a step further. Not only is he a product of Professor X, but also of Magneto and Cable. This gives him a more well-rounded perspective that other X-Men lack, although how they can work that into X-Force may be difficult. Basically, Cannonball is the future of the X-Men. His character arc has been long and interesting, and his relationships with his teammates (particularly a love triangle that developed between him, Sunspot and Tabitha) in addition to his sometimes-rocky father-son relationship with X-Forces founder, Cable, make for some great action outside of the blowing up variety.