my money on the cast of Seinfeld.
Worst "Vs" argument I've heard of?
Magic vs the Force
Imperial Empire vs the Borg
Sailor Moon vs X anime ( have a weird friend who thinks of nothing but strange anime crossovers at work. Also typical of using "Goku" in anything like it's going out of style. )
500-20th Fighters vs 1-20th Planar Shepherd