I have used Gentoo, Slackware, OpenSuSE, Fedora, Red Hat Linux(Ent. Version), K/X/Ubuntu, Slax, Sabayon, Mint, Debian, Open Solaris(Not Linux though), Zenwalk, CentOS and finally settled on Arch Linux.
It has everything I need. Simplicity, stripped down size, great documentation and pre build packages (you know how much time it take to compile packages on gentoo), great community, hand edited config and everything.