I use Binance for trading (cheapest trading) and as a mining pool since it supports ETH, Storj and XMR with static addresses, and now I'm using Gate.io to trade my Chia on.
I use Coinbase to cash out since it's direct to PayPal.
I've never bought crypto with fiat so I'm not sure what the best option is for that.
Reminder that I have a 10%/10% affiliate link for Binance, so if you sign up there we get 10% of each others trade fees as extra tokens in perpetuum.
https://accounts.binance.com/en/register?ref=X1QCXYYB