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
DEX means decentralized while Binance DEX isn't even like that. Take the answer from the owner itself while he can't answer straight with the question on how decentralized his binance DEX is. It's also reported that one of the most favorite dex of all time, IDEX isn't decentralized too.