Magneto vs. Darth Sidious
This would be a great battle. Sidious would definitely fight to kill and be very aggressive about it. What are your opinions? Remember that Magneto's force field isn't a factor here since it has been established that the force can penetrate solid objects as well as force fields. There are many examples showing this in the movies (such as Darth Vader penetrating a galactic ship's force field while he was far away on another ship by choking and killing one of his commanders for failure) and in the story books.