My opinion, Binance will be the best exchange in 2018. Because Binance exchange has a very large community. Beautiful interface and great support team
No doubt Binance is the best exchange all over the world but on the second place for me the most reliable exchange is Okpay. I like their services and the transaction fee is also very reasonable. Many people use different exchanges available in their locality. In my country there are many exchanges but I always use okpay for transactions.