First of all, any altcoin, if taken as a long term investment, it's a huge risk. But if I had to choose, I would consider coins that are not a copy of Bitcoin, and whose innovations make things better, not worse, which is what we see in most altcoins.

I think there is room in the market for currencies that bring a greater focus on scalability and usability, especially when they are technologies that are totally different from blockchain, such as DAG based cryptocurrencies. Take Byteball as an example