Would you buy a Dell desktop, such as the Vostro 320? Why? Why not?
We use Dell at work for desktops as well as other products and I have to say in recent years they are pretty good if all you need is a simple machine.
If you are looking for tweaks, frequent upgrades etc then I would not get a name brand PC.
I helped a family member purchase a XPS desktop from himself recently and they just love it, they wanted something that did the job and did it well but did not want to have to touch the insides for 3+ years.
The only thing is support, enterprise support is fine but I am not sure about home support, you might end up having a hard time on the phone though you can use Chat which helps.
If you are pretty good with computers and don't think you will need support then you it might work out nicely.
Prices are hard to beat now a days that is for sure and the quality of the product is quite decent now.
EDIT: as William as mentioned, format and install a clean OS then you are good to go, that is the most important thing! :)
We are currently using the Vostro series desktops and laptops as well in our organization. I have used the latitudes before and though they are better in terms of reliability, i think that the vostro series are better value for money, depending of course on exactly what kind of users / usage for the desktop / laptops that you are looking at.