CloudFlare (aka. KickassDNS)

A report from SolveDNS shows that CloudFlare has built one of the largest, fastest, easiest, and most resilient authoritative DNS networks in the world, ranking second among providers. The company uses Anycast technology to make its DNS network fast and highly available, with every server worldwide capable of answering any DNS query for clients. This focus on DNS has resulted in a faster, more fault-tolerant infrastructure than traditional registrar's DNS services. CloudFlare is also working on improving its DNS control panel and offering its massive DNS infrastructure to hosting provider partners.