Synthetic vs. dino oil
C++ vs. Java
MS vs. DOJ
Israel vs. Palestine (close 2nd: India vs. Pakistan)
Pete Rose vs. MLB (and the Hall of Fame)
paper vs. plastic
over the roll vs. under the roll
my homework vs. my laziness
the Dukes vs. Boss Hogg (RIP)
Bart vs. Sideshow Bob
MLB vs. MLPA
Washington Redskins vs. Dallas Cowboys
NRA vs. gun control