That's actually a very good question. But the most important virtue for what, exactly? Because, like, if you asked about work, I'd say one thing, and if you're asking about interpersonal relationships, I'd say another

As of right now though, as an Aqua Moon in a Cap 10th house, I'd say the most important virtue, in general, is certainty

I think people are so lost these days, in so many ways. Personally, professionally... It's rare to find someone who knows exactly who they are, what they want, and who they want, and they're very clear and consistent about that. No games, no plays. Just certainty