I have tried KDE on several occasions was impressed with KDE 3.5 but KDE 4 no matter which release seems a little unfinished to work with along a good few bugs thrown in for good measure
GNOME easy to navigate without the gimmicks. Solid Reliable. What more can I say.
My vote most certainly goes to GNOME
OpenSUSE 11.2 certainly seems to be a classy act however personally I would go with Linux Mint
I thoroughly recommend Linux Mint 8 Main Edition which is built upon Ubuntu 9.10 Its easy to install and easy to use plus it comes with much of the software you are likely to need preinstalled
Linux Mint 8 Download
http://www.linuxmint.com/edition.php?id=44
The Perfect Desktop - Linux Mint 8 (Helena)
http://www.howtoforge.com/the-perfect-desktop-linux-mint-8-helena
You download the ISO. image of Linux Mint 8 then you need to create a Bootable LiveCD for installation
Linux Mint 8 can also be run direct from the LiveCD from Booting up without touching your Hard Drive
LUg.