Be extremely careful when using a paper wallet, there are multiple phishing websites that look exactly like the legitimate website, designed to steal your private keys. Some of these sites even appear on the first search link on google.
For detailed analysis, please read our review of Cryptocurrency wallets
Hardware wallets offer the best security for storing Cryptocurrency, it is not recommended to store coins on any exchange for an extended period of time
Note: All ERC20 Tokens such as Omisego, built on the Ethereum network can be stored in any Ethereum Wallet