Fast transfer of money with low or no fees, actually owning your money so that a government or bank can't freeze your account for different reasons. programing your money to do something or go to someone once terms are met through smart contracts on Ethereum, eliminating the trust you have to rely on at the moment with contracts in the real world. You could program your money to be sent to a specific account of your choosing once you die ( if you stop updating the contract once a year for example) instead of making a will and having people fight for what they should get and have people sue each other... Having the information of property on a blockchain, or ownership of your car, decentralised voting systems that cannot be rigged by third parties....Hundreds of use cases, can't list everything here...