Personally, my main factor is mainstream adoptability. Many people I see tend to think of a coin in its possibility to achieve great ROI, and how many people will want to jump on board and invest in it as well so as to drive up the price. In my opinion this is a faulty perception. You should look to see if the actual end usage of the technology the coin/ token represents is something that will be of value to the mainstream public in the future. There's already Monero for anonymity as well as a bunch of anonymous coins out the wazoo so it's almost pointless to jump into new anonymous alt coins promising this or that. Bitcoin has a monopoly on the general digital currency. Ethereum has smart contracts on lock for the most part for running ICO's and new platforms. So basically what will the new technology bring to the game that is a game changer? If it falls anywhere in the realm of the coins mentioned above then it probably won't go anywhere. We have general digital currency, we have anonymous currency, we have ICO platform, and any company can create it's own digital currency on top of those aspects. You want to find a coin that is a game changer that doesn't exist currently that these coins already have a monopoly on. That is what will have people buying that coin and send it to the moon. Beware of shiny white papers that try to make an idea seem unique when it really just falls under what currently exist in one form or another.