I'd rather Morrison had kept him dead, personally, and the gas-chamber Magneto had never happened. It says a lot that Morrison so horribly mutilated the character that they did have to immediately claim that it wasn't Magneto after all. Dying in the flames of Genosha and then the powerful issue with his last words echoed around the dead island would have been a perfect place to leave the character. Post-Planet X was not, in my opinion. It's curious that Morrison made Magneto a far more compelling character dead than he did when he wrote him alive.