Ethereum is also my priority. If we are to base in the popularity, ETH and LTC are my choice, both are solid cryptos. I also heard that Stratis will rocket in few months, so I'm thinking of investing on it as well. While as to price, ETN is a good option, unfortunately, I didn't got the chance to buy when its price is still below 500 sats. But since it's a week of crash, it is the best time to buy.
Can you further explain your reasoning for ETN? I get ETH and LTC but I'm not sure about ETN, don't even know a lot about the coin so I'm just reseraching it now.