I still use Ubuntu by default because I still find it the easiest, so that's what I would recommend. I've been doing CentOS for work (which is basically RedHat for free) and have found it quite nice, but I'm a command-line nerfherder, I just installed the desktop (Gnome) for the first time (I mean, literally, within the last hour), it wasn't too bad. Biggest deal about CentOS is that it doesn't hardly support 32-bit no more, so if your CPU is 32-bit, I would definitely avoid CentOS. Don't know if Ubuntu is the same, though. EDIT: Just looked, it still supports 32-bit with the current distro.