If you are talking about speed , then it should be Binance.com
There must be 10s of factors needed to be considered to find the top cryptocurrency exchange, I mean just being speedy alone will not get all your trading-related issues solved. I am also holding accounts in binance and I'm finding few features which are related to security measurements are good at biannce.
I am also trading at yobit, bittrex, stex and few other reputed exchanges too and I never feel any lag in speed with them. Moreover, if you ask me which is a top exchange in my experience then probably I cannot answer only one exchange as I am good with most of the reputed exchanges.
I'm just confuse why are you trading in a lot of trading website? I will understand it if you are a bounty hunter, and I think you're not? So what's the purpose in a lot of trading websites?
Personally, The Binance is the best for me considering that, Binance is the largest exchange here in crypto world and yes! The speed of binance is undeniably very good. Binance build a reputation here in crypto world so I think it will be always no.1 here. For me, it's just simple the bigger the exchange the better, Because it means that many people are trusting that exchange, and that exchange have a very good service.