I use
Arch Linux for all of my linux installs. It's really fast (even on old hardware), and since you don't need a good de like gnome or kde, you can get away w/ ultralight de's like (flux|open|black)box or the slightly more intensive (but still lightweight) xfce. that's if you need a desktop environment in the first place :D.
install archlinux, dl the latest updates, install xorg, then the de (if you want one). then follow this guide to setup samba on linux:
http://wiki.archlinux.org/index.php/Samba . the only thing i did different was change the share settings from user to share (might be wrong name, but there should be a list, and i'll check my samba conf and post it if you want).