I was re-watching a few Yugioh episodes from the Battle City arc, and I saw a few episodes where two of the villains/antagonists duel each other. I thought it was pretty cool that these villains were fighting each other for supremacy. There wasn't any saving the world stuff, and that was actually refreshing. And then it had me thinking:
What are the most memorable fights/duels/standoffs/confrontations between two or more villains to you?
Since its the most fresh in my mind, I'll mention Yami Bakura vs Yami Marik from Yugioh. It was great because it was two badasses going at it with only evil intentions smirking evilly and everything. Even at the end, the loser still didn't lose face.
You can choose characters that eventually become "good", but the requirement is that at the time of the event, he/she has to be an antagonist.