ETH and XMR.
They each solve problems that BTC doesn't. BTC is good for some purposes, ETH for others, and XMR for others.
I think most people know about ETH and what it does so I won't repeat the info here.
For XMR (Monero), I also think most people know what it is, but maybe are not familiar with why it's the best private coin:
- Fair launch
- Untraceable
- Completely decentralized (vs Dash and others which are semi-centralized, relying on masternodes. If the same entity owns the set of masternodes used to mix your Dash, you can be traced)
- Pure open-source without a trusted setup (Zcash requires a trusted setup...which is an inherent security risk and weakness built into the coin)
