I really like Bittrex. Seems to be one of the better exchanges however always remember never to store your coins on there.
I always store my coins on a hardware wallet. The Ledger Nano S (https://www.ledgerwallet.com/r/fed9?path=/products/1-ledger-nano) is what I have and it is so cool...
My private keys are totally secured offline and no one has access even if my computer is compromised. Absolutely no worrying about my coins being stolen!