Last year it was Ripple and Ethreum which was the most valuable and most profitable altcoins for the investors but what about this year? Which of the altcoins do you think will be most valuable apart from ethreum as ethreum will be the most valuable by default.
Your valuable mean per each coin or total marketcap? 
If you mean market cap, The next i think it'll be EOS. There are many ICO now developing on their platform, and this is a powerful platform for dApps