Apart from reliable ones (Bitcoin, litecoin, and Ethereum) below are my favorites:
1. Waves - It is a decentralized, blockchain based platform, which can be used for trading and various other exchanges. Now it is competing with Ethereum to become the default ICO platform and if that happens the value of the platform would be enormous.
2. Stellar - It is a decentralized payment network that allows cross-asset value transfer by using a distributed ledger on the blockchain. The Stellar project intends to provide a faster, cheaper, and secure platform for money transfer that helps to fill the gap between cryptocurrencies and traditional payment networks.
Always try to see the use and development on the platform before investing rather than their current price.