Gemini is some what good for a cryptocurrency trading, but for all indications the binance will be the very best of the crypto exchange. Binance has the most reputable exchange both in trading volumes or in term of security. Since my entrance into the cryptocurrency industry, i hardly use any other cryptocurrency exchange than the binance. Although, don't keep your coins in any exchange even in binance.
I agree that binance stands out for its first-class protection, but from my own experience, I noted that technical support is not always competent and the speed of work on applications.