RedHat and Novell are only two flavors of Linux. I personally use Debian and things seem to be fine in my camp. Just a reminder, not everything needs to make money in order to be good. Check out Debian and I garuantee you'll never go back to Windows again. Or if your feeling ambitious, grab the hurd.
Would Redhat or Novell or any of the others allow me to load Linux on a PC and add it to a Microsoft network that's running ICS, without being a Linux expert? That's what would get me to try it.