My first introduction to linux was redhat, and then I switched to Windows 2000, then switched to Mac OS X with its BSD-ish core. During my time with Mac OS X, I used Gentoo for my servers. After struggling with upgrades, I decided to switch to Debian at the suggestion of a colleague.
I haven't looked back after switching to debian, but now that I'm using linux on the desktop, I'm wondering if I should give gentoo another chance. I find myself constantly wanting to optimize my computing experience!