I've moved all my domains over to DynaDot (with them over 3 years total). I use DynaDot's DNS for some of my domains and they don't do any funny stuff. Haven't had any problems with DNS outages, transferring domains--in or out, or any billing issues. Their interface is fairly straightforward and clean.

DNS Interface: http://img806.imageshack.us/img806/8523/dynadot.png