The big boy you are looking for is Binance DEX, it is soon becoming one of the DEX with the biggest vol from the development of Binance, like IDO or bonus campaigns and airdrops from projects on Binance that many people trade on. there
what about etherdelta ? i think ed is still the big dex exchange because its older and many people ( bounty/airdrop hunters ) are using this exchange . binance dex in a nutshell is only new on the dex world . and what is that bonus campaign/airdrops you are talking about ? i dont see that binance have a campaign or an airdrop . they are already popular so i dont think that they will need a marketing of thier service . overll best dex for me is still ed and fd