Here are some suggestions : ETH, Ripple, Bitcoin cash and Litecoin. None of these coins will be in negative if you hold for 3 months or more. If you diversify i all of these , you will be safe as well.
I would have to agree that top altcoins are few of the best coins to invest this time as Bitcoin and Crypto Market has been surging and recovering from the major crypto crisis that we experienced since 3rd week of January this year.
investing Ethereum, NEO, Ripple, Cardano, Tron, Stellar and other promising top altcoins in coinmarketcap.com will offer higher profits and rewards than new listed altcoins.
I agree with this too. When investing in altcoins you should be very careful seeing as there are so many scam coins in the market right now and a lot of people stand to lose a lot of money in the long run so it is better to just stick with the top coins and invest in them as they are the least likely coins to fail so you are relatively more safe with them