I personally chose Bittrex and Binance as my two first options. Pretty straight to the point and quite noob-friendly if you ask me, as I've used both since the start of my crypto journey, and never had a problem with both(besides withdrawal fees are quite high depending on which coins). Though you cant trade fiat with both exchanges, only through USDT(tethers).
My 3rd option would be Bitfinex. Why? Because it's pretty much only one of the few exchanges that accepts IOTA.
EDIT: Just found out right now. Didn't know binance already accepted iota. whoops.
I have same reasons with him, have used Bittrex for my first time got into trading, and lately, since bittrex get so many problems, just use binance and it works so well.
But mostly, I use local exchange in my country to trade bitcoin and altcoins, ripple gets so many attentions obviously.
Local exchange in my country is a better exchange compare to most global exchange as it provides a way to deposit and withdraw fiat currency through banks transfer, so easy to do that. Well, people in another country may have same reason with me, such as people in South Korea use BitHumb or people in Japan use bitFlyer.