I'm curious about what altcoins have the most unique or innovative use cases. And I'm NOT looking for MN coins that are going to do a DEX, add governance, or POS coins that are going to be the next Visa, or PoW coins that are going to take over Bitcoin's spot as #1. And I'm not as concerned with the actual coin as the technology / use case behind it. For example, Bitcoin itself was not the wow-factor, it was the blockchain technology behind it.

So. What's going to make me say, "Wow!"?