In this space, we used to recommend CloudFlare’s, 1.1.1.1/1.0.0.1. However, a GeoIP lookup shows 1.1.1.1 is Australia, and we found that using the nines (9.9.9.9/149.112.112.112) gave much better routes for large Axcient backup data transfers. So we’re now suggesting either nines or ISP DNS for maximum results. More when we have more.