It wasn't the hardware the convinced me to buy a mac, it was OS X. A company I interned at lent me a powerbook, and after about a week of using it I had basically stopped using my thinkpad altogether. The user experience of windows XP always felt super clunky and glued together after that.
Also, OS X was my first real exposure to working in a unix based environment. Some people may disagree, but I discovered a definite preference for working in unix/linux. I eventually replaced the OS on my old desktop with Ubuntu, which is nice, but it's still hard for me to imagine a non-technical person like my girlfriend using Ubuntu. However, my girlfriend has switched over to OS X as well, and is much happier than when she was on windows xp. I guess I see OS X as basically being a linux distro with an excellent user experience.
I didn't mind the user experience of XP; in fact, there are a lot of things I still prefer in Windows over OS X.
However, the BSD back-end of OS X has completely sold me on mac laptops as a work machine forever. (I know I can install Cygwin, or switch to an actual linux desktop, but those are the things that feel clunky and glued together to me.)
Also, OS X was my first real exposure to working in a unix based environment. Some people may disagree, but I discovered a definite preference for working in unix/linux. I eventually replaced the OS on my old desktop with Ubuntu, which is nice, but it's still hard for me to imagine a non-technical person like my girlfriend using Ubuntu. However, my girlfriend has switched over to OS X as well, and is much happier than when she was on windows xp. I guess I see OS X as basically being a linux distro with an excellent user experience.
Of course, your mileage may differ.