Gentoo
Historically:
Slackware (first, in the 1990s), then Debian and Red Hat - tried because of updates of software in Slackware, but we couldn't agree :-) then Slackware again (with a BSD try - FreeBSD), and finally Gentoo since 2005 (or maybe even 2004)
Has its downs, not recommended to everybody, one must really like its quirk (its way to zelots), but i wouldn't change it, not yet
I've tried Ubuntu (different distros) and Funtoo - just out of curiosity, not because I feel need to change; Ubuntu's "user's simplicity" is very good thing, but I've always preferred "deep submersion" in the system ;-)
Distro must be amiable from the user's point of view, it is a tool, but liking it really helps
Gentoo
Historically:
Slackware (first, in the 1990s), then Debian and Red Hat - tried because of updates of software in Slackware, but we couldn't agree :-) then Slackware again (with a BSD try - FreeBSD), and finally Gentoo since 2005 (or maybe even 2004)
Has its downs, not recommended to everybody, one must really like its quirk (its way to zelots), but i wouldn't change it, not yet
I've tried Ubuntu (different distros) and Funtoo - just out of curiosity, not because I feel need to change; Ubuntu's "user's simplicity" is very good thing, but I've always preferred "deep submersion" in the system ;-)
Distro must be amiable from the user's point of view, it is a tool, but liking it really helps