I. . . I don't think I would. Even if I completely hate a person, I don't think I could bring myself to do that. Besides, I would prefer to make their life a living hell, filled with nightmares from which they will never wake up and can never escape. Killing them would be a mercy.
. . . Heh, that probably makes me sound a bit psychotic, lol. Well, there's nobody I know right now that I'd really want to do that to.
But there are always those moments of vulnerability, moments when we, as humans, falter, show weakness, even for a second, and would write a name in that Death Note. We'd likely regret it later, but when those moments take hold. . . compassion and reason escape us.
Just my thoughts on that subject, lol.