Take a look at litecoin, Ethereum, Dogecoin, Waves, Bitcoincash and Dash. These are the most trusted altcoins because they are also high in the ranking system so you would think that its safe.
Also a lot of people are using it, because if that was not it then it was really low at the market.
i think litecoin, ethereum, dogecoin, waves and dash is safest altcoins to invest in and fortunately i have some amount for that coins and i think its be a good time to waiting and see the price is up again. although the market conditions is hard to predicted but for ethereum, i think the price is slowly to increase and yesterday the price is reach 0.05 btc and it will be a good moment to make buy and then waiting the other high price.