Gnome for me
I have a dual boot setup with WinXP and Suse 10 with Gnome desktop. I just like the way Gnome looks, and its easy to navigate. I've used both and each has its pros and cons so it really boils down to which you like better. My advice is to get LiveCDs with one of each desktop and try them to see which you prefer before installing one.You may find a LiveCD that offers both and lets you choose which to use, this would be good to test which you like.