Can you suggest me which one is best Altcoin coin hold for 2018? 
Ethereum
Litecoin
Neo
Cardano
Iota
EOS
Ripple
This altcoins are my currently hold for long term and I advise you should make a research before invest, don't just make decisions on what do you heard the other people.
These altcoins are really good for long term hold. I got some last year and I believe they will do much good in terms of giving profit in the future.