Here is an interesting image with the most popular DApps. It seems to me that there is some specialization between them.
Ethereum - smart contracts
TRON - Gambling and Media
EOS - gambling and gaming
NEO - Smart Economy
AION - interoperability and scalability
ICON - Hyperconnected World
WanChain - Blockchain Finance
LISK - javascript Dapp
TEZOS - Self Amending
Cardano - Research Driven
Image credit: Unknown