I use decentralized exchange all the time I want to make use of money. I like Idex.market because of its simplicity and the fees are also low. There are other decentralized exchanges like yobit and token.store.

For me, lately, the favourite exchange is Kucoin. It has very convenient interface and provides the biddings with good liquidity on many assets.
Someone likes such exchanges as Binance and Bitfinex, but I so far didn't even try to work for them.
Also in a Russian-speaking segment, there is a quite good exchange - Yobit.