A lot happen in 2017. We got bitcoin price raise from 1000$ to 7500$ and we got 2 soft forks and as a result got Bitcoin Cash and Bitcoin Gold. A lot of altcoins and ICO were introduce this year. Many countries accepted bitcoin as a legal currency and many existing and new countries accepted bitcoins this   Year . 2018 will take all the growth from the current year and move it one step ahead. Time will proof if 2018 is the best year or now, but for now 2017 is the best year for bitcoins.