Which is the best exchange platform to use ??
It all depends on your region, the coins you are interested in, etc...
I personally am using Binance, Kucoin and CoinExchange. The last one, cause it has new coins faster and these can grow a lot when they hit Binance.
I also have an accoint on Cryptopia, but never used it, and I am verifying my account at Kraken, to convert it again to Fiat money.
I am using all of the exchanger mentioned but I do like Binance since it has a mobile app which is very convenient in my opinion. I can trade fast, anytime and anywhere. Coinexchange is not that good to trade with actually but it is not bad at all.