I bought a pi for a Raspbmc media center, and because I wanted it to do more than the vanilla XBMC, I ended up having to learn linux. I ended up buying a second pi for a Samba NAS and web server.
I've spent a couple years developing with WAMP and dealing with windows BS, but now I'm running an Ubuntu VM and building a dev box for linux.
The pi is ultimately what put me in this direction :)