@CryptoKitties - Need I say more? Built on the Ethereum platform, these silly little "crypto kitties" have actually gone for high prices (https://kittysales.herokuapp.com/), but more importantly they have been testing the limits of the Ethereum network. Many people claim this illustrates the weakness of existing decentralized cryptocurrency scalability (particularly Bitcoin & Ethereum) - but I would argue this has been well known.
Where is the BitcoinCash kitty? https://steemit.com/bitcoin/@the.privatier/12-important-things-you-need-to-know-when-deciding-about-investing-in-bitcoin-cash-or-bitcoin