I often trade in Etherdelta because it is my first exchange and etherdelta is friendly user their interface was great and clear.
I don't think that etherdelta is newbie firendly though because once you made a mistake like in inputting prices and you lack one, you will end up buying usually 10x more than the price and you just lose it. Once you click a button, there is no warning what you will be transacting and no cancel to it so if you made a mistake then you cannot cancel it. I like IDEX more because they have this feature wherein I can still cancel the transaction but there is a limit though to the minimum transaction in IDEX.
For trading in btc,ETH etc I go for binance and bittrex as this are good exchange With high volume so my trade get soon I don't have to wait for long apart from this I bet in other exchange also according to the coin I am holding
I am trading in binance and bittrex too. Others have problems with Bittrex though because they now require KYC so that you can trade there. As far as I know, there are some who weren't able to claim their coins because they failed in KYC. Binance is the most in demand exchange nowadays and coins getting listed there are pumped.