I just tried that distribution chooser and it suggested the following

Gentoo 95%
Slackware 95%
I had a Gentoo system a while back and it was the biggest pain in the ass.
It took 2 days to compile the system and another 2 weeks getting my applications installed. Portage was cool at first, but I found that it was to much of a hassle to install and remove new software just to see if I liked it. In addition, I had to manually edit config files when libraries were upgraded.
Never bothered with Slackware
I've tried the following distros, but nothing really clicked:
RedHat (way back when, about 1997)
openSUSE
Debian
Gentoo
Startcom
Sabayon
Mint
Fedora
I'm currently using
Mangaka Chu it's a Debian/Ubuntu based distro for the Anime community, and my favorite, by far!!

I'm having a great time with this distro, looks like I finally found what works best for me.