They are all good if configured right. There is no such thing as "the best", use what suits you best. Furthermore, some distros may have excellent support (tailor made kernel, etc) for some range of devices (network cards, sound, graphics chipsets, etc) while another distro may have equally good support for another. I use Debian and I love every minute of it, but that's only me. Others prefer SuSE, MDK, Redhat, Gentoo, whatever...