Seeing all the sparring wars between the various fan bases makes me wonder which two fan bases have the most intense rivalry. Certainly there are many candidates for that, and more than I could ever fit onto a poll. My vote would probably go to Virtue & Moir and Davis & White fans though. Wow these last couple years have brought the claws out in both.
Slutskaya vs Kwan, Lipinski vs Kwan, Plushenko vs Yagudin, and Kim vs Asada, are some other standouts for me. Kim vs Asada would probably be my second choice. There are many fans of those two who downright hate the other skater, and many of their fans. Kim vs Sotnikova is one building in momentum, but Sotnikova doesn't even have enough fans right now to make that one a fair fight.