OP didn't specify his capital base (whether he is a money bag or one with a shallow pocket) so we can make our suggestions based on that. All other things being equal I would like to suggest two cryptos here:
1. Waves
2. Tidex token
ethereum, if my recommendation is safe even if the price increase has started to slow. its safe because almost 90% ico manufacture using ethereum platform, so ethereum in my opinion is still good enough for long term.
Yes, we know all that. But ethereum is over used and very expensive now to acquire in quantity. What use is a coin's profit When you don't have it in large quantity.
I would probably recommend ETH and Neo as these two coins are great and doing great performance in the crypto market. These may have a promising future and could potentially give a good return of investment. I would probably buy during bear market such that price value are not that high and later sell during the bull market if I can profit even if there is an increase of 30% from my investment.