I bought my 3G at the Apple store. It had an odd problem where the home button would be very difficult to press when the dock connector was attached. After 3 weeks of ownership, I decided it bothered me enough to make an appointment at the Genius Bar. The tatted-up pierced dude behind the counter verified my complaint and swapped my phone for a new one on the spot without my asking.

That, my friends, is excellent customer service.