Coins that offer staking option seems like the best option for medium to long term investment to me because even if they lose some value, staking reward could cover my loss.
Staking is just a marketing tool to make the price pump. In fact, staking rewards are usually so small to cover losses. I used to hold a decent amount of NEO to get GAS but when bitcoin collapsed, GAS couldn't help me avoid losses. One more problem with staking is that you need to hold a large amount of coins to get a decent amount of staking reward. Although this is altcoin board, I'd like to advise you to buy and hold bitcoin or at least, re-think about your intention in holding staking coins.