I would suggest getting RedHat Fedora Core 3 or 4. It is probably the easiest to install and use. With the exception of nvidia and nforce drivers (and probably ati drivers, but don't know since I don't have an ati card), it should recognize all your hardware without you having to configure the kernel.
I've tried Mandrake as well, but did not like it at all. Had lots of problems with nvidia drivers.
I've also tried Debain 3.0 r5 and didn't like it either. You have to set up the kernel, which is not fun if you are new to linux. (And even after configuring the kernel, I still had all kinds of undetected hardware).
If you do decide to go with Fedora, I would suggest going
here. The link is for FC3, but you can change the 3 to 4 for FC4 (there is also a link on the FC3 page for FC4). All kinds of good info for getting everything set up (like nvidia drivers, java, video codecs, web server, multimedia players, etc.)
A lot of users will tell you to use KDE for your gui, but I would suggest checking out both KDE and Gnome and choosing the one you like more. I personally like Gnome better than KDE. (As long as you have the base for both installed, you can run KDE apps under Gnome and Gnome apps under KDE)
Oh, and another good site for linux is http://www.linuxquestions.org/
Edited, Fri Nov 25 17:22:12 2005 by DataRaider