At this market at the moment, I think there is no perfect currency.
What I am trying to do is to diversify between a few currency. Some in the big ones and some in growing alt coins in which I see potencial.
Also, for stable profit, probably it will be better to have 30 - 50 % in bitcoin. Yes, it is the largest, yes bitcoin is an old news, but the truth is, that still, bitcoin is the coin that moves almost every other coin up/down, so the best way to gain stable profit is bitcoin.