2018 is going to be an historic year for crypto in general. Think long term, avoid day trading. The only coin you mentioned that seems to have long term potential is XVG.

To me a balanced portfolio is going to hold coins that compete with each other for market share. That way when one is down it's competitor is usually up. This should give you a nice steady long term growth as the overall market matures.

Here are my picks;

bitcoin
ethereum
litecoin
steem
stellar

This may look kind of run of the mill but these are the coins I expect to do well. Steem and Stellar are the hail Mary plays.

The big trend for the next few years is going to be 'the programmable blockchain'. This means those coins that add more utility than bitcoin which can be used for the next gen of apps. While there are many that fit the bill, only a handful have a good team behind them. Really suggest you look under the hood with Stellar. I expect it to overtake ripple soon. It's the ripple killer.