because you mentioned GNOME, I'll recommend UBUNTU... you'll have a working GNOME Linux Desktop without much work.
Here's a note that might come in handy for some of you... when I was test driving Ubuntu (both regular install and live cd) I ran into a problem where upon bootup after install I logged into the GNOME desktop and my mouse could move but the keyboard was dead. At first I thought it was a keyboard problem, but it turned out to be a video driver issue. The problem was fixed by dropping to commandline during bootup and then editing a config file and changing the video setting to "vesa" and rebooting. Hopefully this helps someone else who has experienced this problem. I am not sure, but I think it is a problem for some NVIDIA video cards (I have a 6200)...