ETH because of their staying power, I also like OMG though too. The OMG team have said that their tech is going to be able to use fiat, which if it all goes well would be huge. Then there's NEO ... I have mixed feelings on it .. if China comes out with regulations that work with blockchain tech this one I think will boom, but if the Chinese government doesn't have good news it could really hurt this one. NEO from the start has said that they are willing to work with the government too though.