Poloniex is a good exchange overall but needs to improve on support (quality and speed) and web interface/browser integration (I have a very fast computer). Otherwise, it has many pairs and fiat to crypto exchange. Maybe going decentralised in the future is the way for better security also ! Another thing that I would improve (and this is the case for all exchanges) is the graphic indicators wich are no match to Coinigy or Tradingview.