Coinbase is one of the easiest ways to buy, sell and own electronic money, earning the first place on this list. With Coinbase, you can connect to a bank account in the United States and easily transfer money to or from your wallet. You can use these dollars, or convert the new dollars, to buy and sell. In addition to Bitcoin, Coinbase also supports Bitcoin Cash, Ethereum, and Litecoin. There are ongoing rumors of other currencies as ripples get support from Coinbase.