NearlyFreeSpeech has reliable, simple to use DNS service. I've used it for years without issue.

or Nettica

or Rackspace, which is free and has an API

http://www.rackspace.com/cloud/public/dns/

There are many, many options.

Since we're giving options...

For DNS, I recommend dnsimple. They do DNS and domain registration for my three domains and their UI is amazing. Here's a referral link that, if used, gives both of us one month free DNS service (which is only $3 anyway). https://dnsimple.com/r/96a980397648e9

Agreed. I use them as well, and they've been great from day one.

Short anecdote: I have an Icelandic (.is) domain. Iceland's NIC has very strict rules regarding DNS records associated with an Icelandic domain. dnsimple's support team got the problem resolved within a few days. I can definitely see myself with them for the long haul.

We recently evaluated DNS options for our ~800 domains we host DNS for and decided to go with DNSMadeEasy. We're not switched over yet but the deciding factor for me was they're an anycast network and can offer a lot of cool regional responding if we grow to that size. We want to use vanity domains, e.g. ns1,2.ourcompany.com so w/ DNSimple that's only two locations that need to be DDoSed or fail and our sites are down.

It's a fair point (DNSimple is unicast). We're working on building out an Anycast infrastructure, but even that isn't a guarantee for surviving a DDoS. Bottom line on a DDoS: it's a war of bandwidth and the enemy has all the advantages. If you must buy bandwidth and you get DDoS'd you have to pay for that bandwidth, which can be very expensive (not to mention the ongoing operational costs and the ).

Still, we're going to do our best to switch over to Anycast and continue building out our infrastructure as we have the capital to do so.