I just use two copies of bind, one at each of my locations. One I use as the primary for all of the hosted domains, the other for the secondary. All the other servers use whichever of those two nameservers is in the same datacenter as them. I'm also considering switching to djbdns, in which case I might run seperate caches on each server (with the same primary/secondary setup).
Before I ever had any servers of my own and just ran my own personal site, I used hn.org for my nameservers.
I have decided to go for Verisigns dns service. They offer 4 nameservers and works out about $1.50 per domain per month for me.
At the end of the day i dont think anyone will beat their reliability and its cost effective.