Credit: Jason Merritt/Staff Photo: Nathan Fillion Arrives at the Super Premiere on March 21, 2011

No doubt about it, we heart Nathan Fillion (Castle). Big time. And we don’t just obsess over what he does on-screen, either. We like to think we know a thing or two about him outside of his character. What about you? See how well you really know Castle’s front man with Wetpaint’s quiz!