One of our computers is a Dell Dimension XPS, and it's still chugging hard after almost 5 years. the only component that I've had to replace was the hard drive (after 3 years). The kids use it now, as our other two desktops are custom built units that I was able to assemble for less than Dell wanted me to spend on a new XPS.
My previous employer standardized on Dell workstations & laptops nationwide. When you see a company buying from a single vendor to support the computing needs of nearly 50,000 employees, it's a slam dunk vote of confidence. (Well, either that or someone at the corporate office was getting some incredible kickbacks. )