I'm perfectly happy with Debian Stable, personally (I used to use Slackware, so when I need newer versions of stuff it doesn't particularly bother me to upgrade stuff manually). That said, I think Fedora is a much better recommendation for most than Debian Testing or Debian Unstable for a daily driver. I mean, both of those can be used and people do use them (and are happy with them!) but they're works in progress (with all that entails) and are primarily available to help developers with catching bugs so they can be weeded out before the final product (stable) is released. As an actual release, Fedora offers a stability that's not going to be found on either.