Best ROI for Zcash its GTX1060, All depend from money what you can invest to rig.
In today world mining of altcoin is become harder than before because of increasing power cost and decreasing of the quantity of output of the coin due to huge price appreciation. In this situation, I adopted only the cloud-based mining. There is one site that is https://eobot.com which is giving a decent amount of coin per GHS. So, purchase now your GHS before the increase in price. And mind it mine only Dogecoin or any other fast running miner.
Cloud mining contract terms (not to mention that a majority out there are scams) can change anytime and they are paid up front.
Very risky i.e the business can shutdown or take all your coins or cut your contract length from life time to 1 year or six months and you have no recourse.
Secondly, they are VERY expensive compared to mining the same hashrate in-house.
I would only use cloud mining if there's no way I could mine the same algo myself.
