Metroid vs. Vania: Who Deserves the "MetroidVania" title more?

We're only a few weeks away from Castlevania: Belmont's Curse, and only a few months away from Metroid Ravenous. So there's no better time to pit these two franchises against one another! When it comes to the term MetroidVania, there are those out there who believe Castlevania merely copied Metroid's homework with Symphony of the Night. What does history have to say about it? Let's find out!