Rivalries make great television. That's why they're at the heart of so much great television conflict, whether the rivals in question are siblings, lovers, professional competitors or players in a battle of good versus evil. The best rivalries on television involve individual characters that are well-developed and complicated in their own right. Their rivalries are often complex and filled with contradictions. They may have great admiration for each other, but a combination of high stakes, personal goals and fate cast them into conflict with each other. Here are five of the greatest rivalries on television.