I cannot mention on which best altcoins that you mean can easily go 2x in a 1 year.
Well if you want that kind of coins one of I remember is only bitcoin or etherium, This two are most trusted and can get you more profit a 1 year if you hold it for so long.

And in comes of altcoins I dont think so it they have cause of this value of altcoins are in dip always and we dont know on when they start increase the price again.