I have accounts on about 6 or 7 exchanges, and mostly use either Binance and Bittrex (more recently I've started using Kucoin too). From searching around, I like the look of Huobi, seems to get quite a lot of the new coins and has decent volume, plus seems reasonably trustworthy. Are there any other exchanges worth looking at for trading lower marketcap coins that have decent liquidity? Went off Bittrex a bit, they seem to have a hard on for de-listing coins. Not looking to day-trade, but maybe swing trade. Bought into the ICO of Cobinhood and have done a few trades on there, but still not great volume.
It all depends on what coin you wanna buy or sell and the volume especially. So register on all the major ones I'd suggest. But also keep in mind that you have to store your coins in your own wallet where you will own the private keys. No matter how trustworthy the exchange is, using them as a wallet is a big no for obvious reasons. Good Luck! 