I believe that you should never focus only on one coin. Select couple that you would invest in and of course, it all depends from your goal and end game. I like Cardano and XRP, XRP has a great potential for quick turnarounds and money gain. I also like to invest in new projects that I believe in. The project that I have invested recently in is BTCN. It has great ideas, transparent names behind the project and strong and active community. It already reached CMC and is being traded with in a couple of exchanges.