CryptoKitties - Breed and collect adorable creatures using Ethereum
Peepeth - Blockchain-powered Twitter with a soul.
Mars Genesis - 10,000 unique parcels of Mars stored on the blockchain
Minds - The open-source, encrypted social network that expands your reach for using it.
Crypto Corgis - Crypto corgis live (and die) on the blockchain
Ethereum Syllabus - A complete Ethereum learning track, packed with resources