My first distro was FC1 (Dec '03) - I liked yum very much and was in general quite satisfied with it. Then around March 04, I started running into hardware trouble (dust inside the case == overheating etc). I though it was fedora giving me trouble (It did randomly hang on me a couple times). Then I tried to do a distro-upgrade to FC2 and that was the end of it. <insert rant about bloat and double files here>
Up until then, the only thing I had heard about Gentoo was that it compiles everything, and only programmers like it. (this was mostly from the /. crowd, complete with random jokes about compiling everything from scratch)
My most pleasant surprise was when I first run a minimal installation disk and got a very polished looking interface (The purple framebuffer). Tried doing the Stage I install.. which, because my hardware was crappy, kept failing. This *allowed* me to recognize the hardware problem immediately. A quick clean and another memory module later I was doing the Stage I, even as more or less a complete newbie.
In FC, the most *unix* I had done was
Now, granted that I *like* tinkering with computers and building my own box was just a hobby for me, I think going Gentoo has taught me a lot of linux, both for fun and for real productivity. The Gentoo box now serves as a backup storage, a print server, for doing number crunching (as a 3d renderer), as a multimedia server (Internet radio, mp3, DVD and even MythTV). Since then, I've helped a production server move from SuSE to Gentoo, have build a couple small boxes to work as internet radio appliances and am looking forward to making a Gentoo-based Home Theatre system.
What made me come to Gentoo was the cool factor (and the nice bootsplash of the LiveCD). What makes me stay is the forums. For my part, I give 2 cds to anyone who wants to go linux. One is Knoppix, the other is the Gentoo LiveCD. It doesn't get any easier than Knoppix and doesn't get any more powerful than Gentoo.