I've had my MacBook 2.16GHz for just under two years now, and I've just had to replace the hard drive for a second time (mind you, this time not under Apple's warrantee).
With most laptops, this would not be much of a surprise to me - after all, most laptops tend to take a beating, and this type of failure is somewhat normal. The thing is, this laptop is used almost exclusively for testing; it sits on my desk 340 days of the year without moving - the power cord is tie wrapped to my desk even.
If my friends are reading this, they're probably thinking "Steven is on one of his anti-Apple rants again," and while that might be partially true, the point I'm trying to make (or the myths I'm trying to dispel rather) is simple: MacBooks are not more reliable than Dell, HP, or Lenovo laptops. They all use almost identical drives, mother boards, video cards and RAM (the RAM I pulled out of this recently was Samsung).
That being said, my experience with this particular MacBook is that it is actually significantly less reliable than other laptops I've owned. My general feeling is that it suffers from a heat dissipation problem. The vents on this unit are few and small, and under most of my use, the fan has to run at what seems to be full blast. When I compare this to similar Dell laptops that I've owned/used, they seem to have way better ventilation, and as a result, the fans seem to run less frequently.
Good thing new drives are cheap!