You should not use any trading platform. Most "good" coin are ERC20 tokens and can be stored on individual cold storage.
Only use the trading platform to transfer paper money (euro, USD ...) to digital money and vice versa. Keep your Bitcoin and other currencies offline.
Here are my top exchanges as of now. #1 would be BITTREX and second would be Binance. Most of the good ICO's and alts are listed in these exchanges. So I can personally vouch for them. You can look for other exchanges too, but i suggest that look for the ones with good alts that is available for trading.
