There are some really promising coins at the moment, right now I would be looking to buy ethereum, electroneum and SIA (it is super cheap right now).
I second this, ethereum for me is second best coin to buy because of the cheap price but for me Bitcoin is still the best coin though its not good idea to buy right now because of the high price but once it goes down again that will be the best time to buy bitcoin and wait for it to increase again which is very worth it. Bitcoin really give big profits compared to other coins.
Every person has their own choice, I think there are so many other potential coins, which can really give you a good profit. Although in presnet time i do not think that there is any other currency which can give you such a good profit that we can expect from bitcoin i think in present bitcoin is the berst option to trade in present time. because bitcoin price is expected to increase more.