I only have experience with cryptopia and Binance for alt coins.
Cryptopia used to be very good before for mainly two reasons:
. You were able of trading in LTC market. One day suddenly, without any notice, the LTC market stop working. I have to remember that some coins were listed only in LTC market. It took them around three weeks to list that coins in the BTC market.
. The minimum trading amount was lower before also. Now I have some coins that I can not withdraw because I bought them with LTC and now the minimum in BTC is higher.
 
Trading fees are low, but be aware of the withdrawal fees. Kukoin for example has lower withdrawal fees.

In conclusion, if you want to trade, cryptopia is ok, but if you are thinking on hold the coins in your wallet, maybe is better consider other options.