User Interface

Suse 10.1 is the best looking Linux available. Actually you can Theme any Linux
and make it look good!!!! For Installation , allocate 10 GB for 'root' & 1.5 GB for swap.
Swap is the Virtual Memory (in Windows terms). If you are totally new to Linux, then
leave 10 GB of unpartitioned space. During partitioning, choose the option "Allocate
from the free space available". Suse will do the partition allocation for you.
Choose GNOME as the Window Manager during Installation. That's all!!!

Well if you are looking for bestlooking I think SuSE and MAndrake stands on the sme plateform,

But i like Ubuntu, It's awesome.

If you are lazy and don't want to do anything then check out FoxxLinux. It has Os X like interface.
If you want to customise use the following sites
GNOME - www.gnome-look.org
KDE - www.kde-look.org
XFCE - www.xfce-look.org
Or any such site.
Another way is install XGL, which will give you 3D desktop. Nothing can match the good looking UI of 3D Desktop. If you have a decent NVidia graphics card, you can try XGL on Suse 10.1.

which is better looking-GNOME suse10.1 or KDE suse 10.1

That is a matter of personal preference. But, if you have a NVidia graphics card, XGL on GNOME in Suse 10.1 will beat KDE in terms of looks.

KDE has Gloss, Gnome has Simplicity. Choose one path or choose both.

Knoppix

Ya. Knoppix (the latest one) looks really good.

looks=Suseeee

I like enlightment.. Gives a mac like feel and very light on resources.. You can use either E16 or E17