I have been doing research on DNS for my project. And below are some of my findings / Opinions.

I am not going to paid a large sums of money on DNS. And that rules out some of the options like Dyn.

You want a 3rd Party DNS mainly because of HA and Speed. Route53 and OnApp hosting's DNS do really well, but they are slow in some areas.

DNSMadeEasy was the best i could find, it doesn't have any PoPs in Asia areas, but other then that it is pretty much the fastest DNS services in US and EU. And it is surprisingly cheap as well for the low to Mid traffic. Expensive at the Higher End compared to Route53 but i guess it wouldn't matter much when you reach that sort of traffic.

I would actually love to use CloudFlare, you get free DNS + analytics. For Personal site i think it is great. For anything business related i still have doubts. They have expanded quite lot of areas over the last 6 months. But last times i looked its speed aren't great compared to OnApp or Route53. Its downtime is also higher.