I just got a PowerBook G4 for Christmas and LOVE IT! Plus I have a school computer that the state gives every kid in my grade, just for the school year but we can take it home and everything. That's an iBook and not nearly as cool as my PowerBook.
Seriously, I am a graphic designer. I use and abuse several macs all day every day. I have had one...ONE...in over 17 years that had hardware problems. In that same time period, I have had ONE...yes ONE...virus.
I also have used windows machines. I have one in the office I have to use for my shipping software of when someone brings in a Publisher (gag!) file I have to print from.
My girlfriend's HP caught on FIRE. She has gone through 3 windows machines in 5 years. We tend to use Macs until we upgrade and then find a non-techie relative that needs a nice simple low maintenance machine to use for email.