Look for ideas that robustly resonate.

Robustly resonating: nearly everyone who hears it is intrigued.

The more diversity of people you find who resonate with it, the better: the more likely that the next person you talk to also resonates.

An idea that many people from many different perspectives have an "aha" moment for is more likely to be interesting: surprising and potentially valuable.

If you find an idea that resonates with just about everyone, it's a great idea, with the potential to go viral and change a lot of beliefs quickly.