My favorite is Binance.  I like the 2 BTC withdraw limit for people who wish to remain private.  I also like the volume on the exchange.  I can get in and out of positions worth a few Bitcoin without too much fuss. 

My least favorite exchange is Huobi.  They have an unwritten rule on every coin thy have and it states a yearly withdraw limit.  This information is no where to be found.  I was harmed by this rule.  When I told Huobi this was not fair they told me to pound sand and wait the year out.