We have been in the computer service and repair business since May, 1986. We would not call the Dells bad as a group, although they had bad motherboards in the 2200, 2250, 2300, and 2350. Where we have seen hugh failures has been in an enormous number of Sony VAIOs both desktop and laptops, low end HP's, low end Compaqs, and a very few of the recent Gateway desktops.
Laptops: All eMachine laptops; most Compaq laptops, Most Acer, and most Sony VAIO laptops have very early and expensive failures. Certain Dell Inspiron laptops have high failures. IBM
The good laptops are most IBM Thinkpads, most upper end HP, most Dell Latitudes, most upper end Compaq Presarios, and most upper end Dell Inspirons.
Most laptop failures are due to bad to very bad cooling systems, bad to terrible inverters for the LCD screens, and poorly designed fan and air circulation. Certain Hard drives have high failure rates, such as the Hitachi and IBM Travelstar. Others are superb such as Western Digital, Fujitsu, Samsung, and Seagate Momentus.
It is time to begin posting the bad models to some sort of list where people can learn about their potential "investment."