Quick question for the #Linux buffs.

**For when you want something that packages the most up-to-date software you can get, what's a good distribution these days?**

#Debian sid? #Arch? #Gentoo? #Fedora? Something else?

I'm not looking for a daily driver distribution here, but rather something I can drop into a VM when I want to test something on as recent versions as reasonably possible of stuff.