The right choice is currently buying the top 5 coins because the price has an effect on the market and has a greater growth potential than other altcoins, especially ETH and I hold ETH until the target portfolio is reached.
Top-5 coins are good for a long-term investment. Those one who want to make a fast profit need to take a risk and buy low-cap, unpopular altcoins. Some of them are conducting IEO, thus they are pretty perspective for a short-term investing.