Depends on the amount you want to buy or sell. For a small sum, just use LocalBitcoin. For higher sums find a good exchanger. Exchange websites offer good limit plans and you'll save a lot of money, or a lot of cryptos, depending on your point of view. Here's the way to go option BTCBIT.net . Take a look
I use a special platform for investments and cryptocurrency exchange. It was cryptowatch that opened my eyes to what a really good platform is. This is when cryptowatch fees are small, you can watch charts in real time, no delays or problems, charts for more than 25 cryptocurrency exchanges and much more. Take note)