Most of the exchange which I used most often are Binance, Kucoin, Hitbtc, Livecoin, Coinbene, Coss, Bittrex, Idex, Cryptopia, Houbi, and Okex, those are good to me in my opinion. But still there are lot of exchange out there which I think you can probably choose that the best for you, you can check it at coinmarketcap.
Shapeshift is basically decentralized and has been around forever. Erik voorhes is the owner of shapeshift and he has been a trusted reliable guy in the crypto market so I will definetly suggest any company he has created so far. Dude has collected insane amount of money from people (at the amount of 50k bitcoins, not 50k dollars worth of bitcoin, literally 50 thousand bitcoins) and repaid everyone back with interest when he sold his satoshidice company.
He managed to make close to a billion dollars from his crypto works so far and get out at the perfect time when satoshidice was getting worse and worse and right now he probably couldn't sell it for a thousand bitcoin if he wanted to. He built coinapult for debit card systems and with bitinstant, right now shapeshift is his main focus and it has been a known great company so far.