@adamtrmm:I didn't want to add New Mutants or X-Factor (besides pertinent crossover issues) because it's an X-Men focused list. I wanted something focused and to the point. There is still plenty of New Mutants to be had in this list though: Professor X is a Jerk issue, Fall of the Mutants, Asgardian Wars, and X-Tinction Agenda.
@invain: Yeah, my first time around I missed all those mini-series as well. I just finished a re-read of this whole list and it was nice to go back and read it in context of what was happening around it.