I have used a lot of exchanges like Binance KUcoin BYbit Pancakerswap but the worst one is p2pb2b. this is a very worst exchange for me because when I use it, I always got lost because of its chart.
Never even heard of that exchange and at first sight, I thought you are paying p2p trades haha 
.For me the worst one has to be yoshit because they are shit and list any coin plus the exchange is a well known scam and while I didn't got scammed, I never had an easy time trading there.
I think the best one has to be Binance given how picky and careful they are when adding new coins and while their support sucks, there aren't many problems I have had on this platform for over a year or two now.
For overall on being shit they Yobit does have that which does have shit support and very shady acts which the community does aware about that specially those old users here on this forum.
Nothing beats out on being shady on this platform but still surprisingly it is still running until today.