For inexperienced users, who cannot manage upgrading programs in Debian Testing or Unstable without breaking their system, Debian Stable may be the best choice. In Debian Stable you don't get the chance to do those hazardous upgrades very often.
On the other hand, you could learn to upgrade Debian packages the proper way, by installing apt-listbugs and refusing to upgrade specific packages to newer versions as long as they are reported to be buggy. It might also be useful to learn to use aptitude, which is a great tool for choosing packages to be upgraded (in smaller amounts than 100 packages at a time) as well as for holding packages that you don't want to upgrade. This option is a bit more toilsome but it enables you to run a relatively up-to-date Debian system without breaking it.
Or maybe you'd like to try a new Debian based distro, Ubuntu, that is supposed to be upgraded once every six months and in between these upgrades you'll only receive security fixes. That sounds like a good option for many users who find maintaining an up-to-date Debian system difficult, but Ubuntu is still a fresh distro and only time will tell if it lives up to expectations.
In many ways Debian is a safe choice. It doesn't have one lead developer who could fall ill and it doesn't rely on a financier who could run out of money or otherwise lose interest in backing up the distro. But before you can truly enjoy this safety and the Super Cow Powers of APT, you're going to have to learn to do things The Debian Way.