So many great responses here, hey Linux is great!!!
My first experience with linux was an install of the current version of Red Hat (ver 7.2). Since then I've messed around with a lot of distributions, some for a long time, some not so much. My first experience with Gentoo eventually resulted in a sucessful stage1 install of 2004.1, I think I still have the manual I printed. I first looked at Gentoo for the same reason I ran Slackware, because I read that you would learn a lot about linux using it.
I have a wife and two teenage daughters, and Windoze has not been allowed in our house for about 5 years. Despite the fact that Gentoo appeals to my inner need to tinker and tweak, I kept trying distributions that I thought would be easier to maintain and provide all the things that high school teenagers and working moms want/need in an operating system. Ok, so some distributions I've tried just because they seemed cool (Puppy Linux, come on, how can you not try it??

).
The biggest single reason I kept coming back to Gentoo, and why it has been my main distribution for some time now (ok, I still have one machine running Ubuntu) is that Gentoo is the only distribution that always provided a Gentoo way to do anything I have wanted to do with a computer. Everytime I want to do something, or run a particular program, or use a particular piece of hardware (old or new) I've been able to do it "the Gentoo Way" without going out and finding someone else's hack, or going to someone elses repository, etc.
I also really like the whole "fix the system" philosophy as apposed to re-installing.
I look forward to using Gentoo for many years to come...
"... and if that doesn't work, CONGRATULATIONS!!! You're about to learn a whole lot more about linux and your system hardware!"