We have dells here at my work. Hard drives are the only thing the seem to be a problem for dell like others have said. Although you get a nice flat panel free and warranties are easy to work with. Talking to support in India sucks though...
Dell uses WD hard drives yes, and we have had them go out every once in a while. BUT I have built 4-5+ machines for myself and others and I do not use WD hard drives anymore. They are just crap, nanosystem uses these too so you guys that think only Dell uses WD drives are wrong. Unless you specify nano uses WD too. Yes there are different WD drives, but in my experiences do not use one. I switched to Seagate and well see how that goes for me.
If you have the money get an IBM.
Otherwise build one cheap at nano, or get a decent dell. All good choices.