I'm curious about OpenSolaris.
BuddyCianci wrote: Solaris is an SUS standard UNIX. I've read that OpenSolaris is based off the code, and they basically use the Solaris code to make it. So it must be very UNIX. I don't know about available software and hardware compatibility, but I can't imagine it's not a real quality OS.
You might want to get a cheat sheet of helpful Solaris commands handy before you try the live CD. I'm unsure what version they're on now, but Solaris 9 was infuriating for me because some of the scripts to activate network interfaces didn't use identical commands to what I expected.
Beyond that, looks nice and everything. Wish I had more time to play around with it. The few jobs I see available on sites for Sol. operators seem to stay up longer, so if you're interested in doing it as a career (in the future) I do think there is a significant shortfall in the number of capable administrators.