I've had 5 Apple laptops since 2001 and have never had to replace anything. Average time of ownership has only been 2 years, though. Because of the resale value, I've found it's pretty effective to sell the 2-year old and put it towards a new one.
I'm, like, a slobbery fanboi and I can tell you, occasionally, Apple makes one that's rotten.
I've since switched to another laptop manufacturer.