Only 2 exchanges are the best for me, first poloniex and bittrex though there's another contender which is shapeshift.io
Don't use yobit.net as it will just going to give you some headache in terms of their support.
They are the worst exchange after all.
Don't use Poloniex. They have huge problems: users lost their funds there
Well just go with the second choice which is bittrex and shapeshift.io and good thing here that so far I haven't seen suggesting btc-e.
We know that they have also a problem today.
Bittrex will be a good choice.