Make sure you really have to kill your nemesis. If you can seriously discredit him/her, fine. That adds insult to injury and is probably more satisfactory than killing your enemy outright.
Of course, if you want to really end it, do it yourself. No henchmen, robots, blackmailed people, or remote-controlled devices. No doomsday devices, no elaborate stab-the-victim-through-the-phone inventions, no Saw games, no high-tech crap that miraculously fails at the worst possible moment.
Even though at the core of your being you want to prolong the suffering of your nemesis -- don't. Find his/her kryptonite and get rid of the fool. Nobody messes with a villain who's actually doing something about his enemies other than developing elaborate schemes that always fail.
Of course, if you want to really end it, do it yourself. No henchmen, robots, blackmailed people, or remote-controlled devices. No doomsday devices, no elaborate stab-the-victim-through-the-phone inventions, no Saw games, no high-tech crap that miraculously fails at the worst possible moment.
Even though at the core of your being you want to prolong the suffering of your nemesis -- don't. Find his/her kryptonite and get rid of the fool. Nobody messes with a villain who's actually doing something about his enemies other than developing elaborate schemes that always fail.