I personally use Binance and Yobit because of thst fact that both of these platforms are widely accepted by everyone. I once used Poliniex and I must say that it offers a great experience as well. If you want assurance, go for Binance and Yobit. 100% legit.
I just chose Binance because this exchange has a lot of potentials for you to make a profit here, and when using this exchange, all your trades can happen very fast without spending too much time waiting. Also, I also use more Huobi because many people appreciate this exchange, and the liquidity here really always makes me feel very impressed.
Each exchange has its own strengths, but I prefer using Bitmax because this exchange also has a lot of good investment options and is easy to use. Of course, it cannot be compared to exchanges like Binance or Huobi because these two exchanges are well known when participating in this market. What I like most about Bitmax is the low withdrawal fee and all transactions at this exchange are very quick and never make me feel disappointed here.