If you have a lot of domains (or willing to pay a premium), I am a huge fan of Fabulous.com. Good support, good pricing, my impression is fairly secure. They have an executive lock feature:
Executive-lock (E-Lock) allows for the domain name to be frozen. This means that the domain name is:
1. Unable to be transferred out to another Registrar.
2. Unable to be pushed to another Fabulous account.
3. Unable to have changes to its nameservers.
4. Unable to have the registrar-lock status removed.
You can define whatever conditions you want and they manually do them if you want it unlocked. It could take many days to unlock your domain, but it definitely isn't going anywhere.
They are focused on large portfolio customers. That's kind of the caveat for their service. Many of those large customers also use their other services like domain parking too.
Executive-lock (E-Lock) allows for the domain name to be frozen. This means that the domain name is:
1. Unable to be transferred out to another Registrar.
2. Unable to be pushed to another Fabulous account.
3. Unable to have changes to its nameservers.
4. Unable to have the registrar-lock status removed.
You can define whatever conditions you want and they manually do them if you want it unlocked. It could take many days to unlock your domain, but it definitely isn't going anywhere.