Hey guys!
I sometimes find it difficult to get a good overview. So I put this little comparison of some of my favourite Projects together. Maybe it also helps someone else ;-)
(There are so many more to pick from! If you want to find out more: my favourite resource is https://parachains.info/auctions)

Polkadot’s parachain model was designed with the belief that the internet of the future will have many different types of blockchains working together. Just as the current version of the internet caters to different needs, blockchains need to be able to provide a variety of services (like gaming, identity management, finance, etc.)
Parachains allow any type of data or asset transactions to be spread out and processed in parallel over an ecosystem of specialized layer-1 blockchains, significantly improving throughput and scalability - opening up a host of new use cases and applications.

Acala is a scalable layer-one smart contract platform. Ethereum-compatible and optimized for decentralized finance Acala provides built-in liquidity and ready-made financial applications. With the Acala Swap trustless exchange, the Acala Dollar decentralized stablecoin (aUSD), DOT Liquid Staking (LDOT), and the Acala EVM+, Acala lets developers access the best of Ethereum and the full power of Substrate.

Moonbeam is an Ethereum-compatible smart contract platform that makes it easy to build natively interoperable applications. This Ethereum compatibility allows developers to deploy existing Solidity smart contracts and DApp frontends to Moonbeam with minimal changes. As a parachain on the Polkadot network, Moonbeam will benefit from the shared security of the Polkadot relay chain and integrations with other chains that are connected to Polkadot.

Astar Network is a multi-chain dApp hub on Polkadot, supporting Ethereum Virtual Machine, WebAssembly, layer2 solutions and multiple layer1 blockchains. Since Polkadot Relaychain doesn't support smart contracts by design, Astar provides dApp developers a high-performance smart contract platform with scalability and interoperability between multiple virtual machines and layer1 blockchains. Astar has organic dev growth with teams building synthetic assets, stablecoins, a multichain DEX, etc.

Parallel Finance is a decentralized money market protocol that offers lending, staking, and borrowing in the Polkadot ecosystem. Depositors can lend and stake simultaneously to earn double yield on their staked assets, and borrowers can collateralize to borrow.

Litentry is a Decentralized Identity Aggregation protocol across multiple networks, it features a DID indexing mechanism and a Substrate-based credit computation network. The protocol provides a decentralized, interoperable identity aggregation service that mitigates the difficulty of resolving agnostic DID mechanisms. Litentry provides a secure vehicle through which users manage their identities and dApps obtain the real-time credit/reputation of an identity owner across different blockchains.

Manta Network is the on-chain privacy solution for crypto assets build from the first principle. In short term, Manta will be a product that enables high-performance private DeFi transactions and AMM styled swap. Manta will be the privacy-preservation platform for all Web3 applications. Manta’s founding team comprises crypto veterans from Harvard, MIT, and Algorand. Manta has previously completed million-dollar rounds of financing.

Clover Finance is focused on cross-chain compatibility for DeFi applications and interoperability between different blockchains. It will bring the most advanced and seamless multi-chain decentralised finance experience to its users. Clover Finance is pushing to become one of the fastest-growing projects of the Polkadot ecosystem. Clover wallet suite is the first multi- and cross-chain wallet that supports simultaneous connection of networks.

Bifrost is the Polkadot Ecological DeFi basic protocol, it's also one of five Kusama parachains in the first batch. It is committed to becoming an infrastructure for pledged assets to provide liquidity. It has launched a derivative vToken for Staking and Polkadot Parachain Slot. It has obtained $2.15M in fund-raising from NGC, SNZ, DFG, CMS and other institutions and Web3 Foundation Grant. It is also a member of Substrate Builders Program and Web3 Bootcamp.