I don't advise using anything other than CoinBase. As of recent, major exchanges such as Kraken and Poloniex have had major crash issues, and have cost investors hundreds/thousands of dollars due to their delays. They also have extremely poor customer service. Coinbase at least will answer your question within 2 days, and they are insured. Therefore, if they were to ever experience a hack, their insurance policy will compensate you for your loss. You can read more here:

https://support.coinbase.com/customer/portal/articles/1662379-how-is-coinbase-insured-