Arch, Slackware, or Gentoo?

The age-old question for serious Linux users who want a lightweight distro. I've personally been running Arch for a while, but have been messing with beth Gentoo, Slackware, and many other distros through VMs. I really like Slackware, but the community of Arch, and proportionatly the software developed and released on the, let's be frank, fantastic AUR is seemingly massive compared to the Slackware userbase, which is still rather large. Then, there's Gentoo to consider, which seems like a really hands-on distro, but not as lightweight, almost pointlessly hands-on...

Thoughts, opinions?

If you are into Arch and Libre, I would recommend checking out Parabola. :)