The perfect murder is one you can cover up with money. The method itself doesn't even matter as long as you are in a place of power and you have a lot of useful connections.
You freeze a plastic coke bottle full of water then slice the plastic off & clobber someone over the head with it in the bath tub then throw the ice bottle in the tub to melt.
Break in to an old lady's house (one with connections is best) on a Saturday night. Take her from her bed, and disappear into the Arizona night. Mess with the cameras a little bit, and count on idiots sending in random ransom notes while you run.