I use Bitstamp, they do not offer the lowest fee rates but the interface is super easy and they offer security and strong capitalization plus excellent support. Sometimes they tend to hold some transactions longer than needed and to stall with additional verification which can be annoying. At the same time I use https://fox.exchange/pair/BTC-ETH. They offer instant exchange orders between coins so it comes useful every time you need to switch your coins since they do not demand any further verification. Instant, easy, with full anonymity.