Altcoins that are worth to hold for 2-3 years are NEO, ETH, WAVES, ADEX, XEM, OMG, STRATIS. These coin has a big potential to grow more with a great developer and team.
Yes, most of the coins above show the good growth rate in between and can be seen often among the top list of the trending big gainers of the coinmarketcap. I've plans of holding Eth, NEM, Waves, TAAS, deep onion and few other coins that are very low in value.
I'm losing hopes on waves , it's already been down on 0.00067862 btc price. Sadly, I bought my tokens when the price is at 100k satoshi.
I wish I could turn back and buy on this time and have a better chance to double my funds when it goes back at that price again. Too much downward slope on waves price graph.