I think Bitcoin cash and Litecoin are the possible competitors of ETH since they were also getting popular now. Litecoin though has smaller price but it looks promising and has potentials. But I think ETH is still better than other altcoins.
Well, I agree on Bitcoin Cash, LiteCoin are two of the best competitors of Ethereum but for me it's NEO as it is also the mother of the smart contracts that became some of the top altcoins in coinmarketcap.com
Just like Ethereum, NEO is fast, scalable and reliable and I think in the future, NEO will surpass Ethereum's market cap.