In my opinion, top 10 best altcoins for 2018:
Ripple
NEM
EOS
Litecoin
Monero
Steem
Spectrecoin
Cardano
Elecrtronium
Substratum
I might probably erase Ripple from this list but add there Lisk, And Komodo. OmiseGO is also great for the future investments. Do not forget about TRON and ICON. This stuff is also interesting:
https://www.youtube.com/watch?v=llt6zG4J6wg