Typically I do not recommend buying any crypto other than Bitcoin and Ethereum, but after due diligence, I am slowly becoming a fan of DOT. Polkadot offers cross-chain interoperability which allows various blockchains to share data and communicate with one another, all in a trustless manor. Polkadot connects all blockchains via its relay chain, parachains and bridges. Polkadots relay chain keeps record of all network transactions, parachains connect individual blockchains and allow them to run simultaneously. This enables scalability while increasing network transaction speed and allows customization. Last but not least, Polkadot uses bridges, which allow current and established blockchains (like Bitcoin and Ethereum) to communicate with the Polkadot network. Because of this, I can see Polkadot becoming a serious contender in the crypto space in the coming years.