GDAX is the way to go. I also like Kraken, if they could keep their site up for more than 5 minutes.I get my bitcoin at Abra now, they have a bunch of "virtual" crypto but you can buy and withdraw Bitcoin and they have been completing my orders in 2-3 days vs. 7 days every time on Coinbase. And most importantly your not being charged an arm and leg for fees for the purchases which is really nice when your buying small amounts.