I think Gentoo is the best distro around for anyone who needs fine control over his system. If you want a somewhat exotic setup, specific requirements, or simply the feeling of utmost control over your system, Gentoo is the ticket. It also makes you
learn about Unix systems, and provides one of the most savvy communities I've encountered.
That being said, I've converted my main system to Linux Mint recently, an Ubuntu compatible spin-off that provides all the plug-ins, codecs etc. that Ubuntu itself shies away from because they are (*shudder*) "not free enough". The reason was simple: It's more instructive and fun to get it all running under Gentoo, but I no longer have the
time to do so. I needed out-of-the-box functionality, and Linux Mint was the ticket.
At the office, we've got a quad-core running a XEN host and several virtual machines on a RAID setup, including a /home shared via NFS across all VM's... and here, Gentoo is still the #1 choice because you can make it jump through loops at your command.
If you know what you're doing as there are no "wizards" or "assistants" to do it for you, except (as I said) its excellent community and web resources.
We've even written our build scripts as Gentoo Portage-compatible .ebuilds, including a script to run them on non-Gentoo Linuxes or AIX boxes.
