Cryptopia is now accepting new user registrations, so if you haven't opened an account with them hurry up before they close again! This crypto exchange is the only one which has the biggest selection of altcoins.

https://cryptopia.co.nz/

Important! Register with multiple crypto exchanges so you can leverage their different benefits:
https://www.coinbase.com - Purchase Bitcoins, Bitcoin Cash, Litecoins or Ethereum with USD ($) with both credit cards and checking accounts.
https://www.binance.com - Offers various different alt-coins and and does not mandate user identity verification.
https://cryptopia.co.nz/ - The biggest selection of alt-coins
https://www.kucoin.com - Offers the crypto coin KCS which pays dividends to its users.

Thank you for the up vote! :)