I use Debian Etch (x86_64) for a few months now, on a AMD Athlon 64 box (not the fastest hardware in the world nowadays) and I'm quite satisfied with it. I also use Arch on an experimental server (old pentium4) and that's also good for the purpose: light-weight, no unneeded extra's.
So in my opinion the question is: what do you want to do with it? Then make a choice for hardware & distro. The benefit of Linux: choice!!

Too much choice .
Thanks for all of your replies.
I made a list of all the kernel mods I need and I'll try it out again.
Probably wont go to Arch VooDoo unless the Final Hardy LTS disappoints (I don't think it will, the new nautilus and stuff looks amazing).

i made a webserver

i have a tutorial here somewhere about making a debian based webserver

http://www.daniweb.com/forums/thread78131.html