EDIT: GO WITH x86!!!! 32bit is better, 64bit cannot support as many apps! It does not have wine, cdrdao, and many others. Any commercial softwatre WILL NOT work unless it was compiled for 64 bit. Please use x86. x86_64 is not much faster!
I recomend mepis. It is easy to use, fast, and stable.
It uses the best gui imo, kde. It is better than most distros because it uses its own, and debian's huge software repository. It is based on knoppix so it has exelent hardware support, and video drivers are built in. You just select ati or nvidia during installation. Another great feature is that it has a live cd from which you install from. This serves as a great rescue tool. It is a distro that is made for pros and noobs alike. They have a great support forums too.
Good luck with linux,
Sevoma