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.
Saved crypto, but they're the reason I decided not to invest in Eth. Right before it rocketed from 420 to 700.
FML. Feels bad, man.
you should stay with eth bro, always analyse the market