What's your favorite OS?
I spent several years as a UNIX admin, and Linux has been my desktop OS choice for quite a while. However, when the Mac mini was released, it was enough to get me to buy my first Mac. Since then, I've totally converted my family to OS X.
i really like OS X, but I hate touchpads. So my mobile solution is a thinkpad + Ubuntu. When I get home, I'll likely buy a new Mac desktop though.