I'm not using CentOS, but how often do you need to update? What are your needs as far as software is concerned? If you tell us what packages you'll need, then we'll probably be able to steer you toward a good choice.
You might do well to put on an old copy of Fedora Core 1/2 or Ubuntu Warty. I've been running Ubuntu Warty on my server for the better part of a year now, and whenever I run an apt-get upgrade it's a big thing to see anything that needs doing. Updates are few and far between, and it's been nothing but stable for me. The only updates that get sent my way are security updates which is usually exactly the same software sans one vulnerability, and I want those anyway.
You might do well to put on Debian Stable as well. When Debian says stable, it means _stable_.