Which is the best altcoin exchange
I think that the best service will be the one that does not require registration and account creation. Many have problems with blocking accounts, so you can lose your funds.
Other than that, we need to have security for our coins because it will help us to protect our coins. Exchanges which has higher volumes and already listed some potential coins will help to increase more demand in the market.
to secure our coins we need to store it on our own wallets instead of exchange's wallet. if you don't have access to your private key - it's not your coins