Cryptopia exchange I used and felt safe. However, the trading volume of cryptopia is quite small so the liquidity is not good in some altcoins. Please see the trading volume of the altcoin you want to trade before using. This exchange is improving quite a lot, but there are quite a lot of garbage altcoins, the support team is not very good.
I'm a moderator on Cryptopia and have been trading on site for 4 years. Cryptopia is a reputable, safe exchange that takes security seriously.
They provide multiple options for users to secure their accounts and have launched a new SUPPORT CENTRE to educate their users about how to properly secure their accounts.
Customer Support has improved greatly in the last 2-3 months as the CEO has made Customer Support a priority.
The site is by no means perfect but they're constantly improving and making the user experience better.
Stop by the Trollbox and say hello.
It's a friendly place with volunteer Moderators & long time users that will answer any, reasonable, question you may have about the site.