I have built 2 computers, my wife decided she wanted a dell like her 2 sisters got. They have had many problems. A friend of mine bought a dell, said "if you build one yourself you have no support and you don't get the anit virus software(and other software). He has had many a virus, I have not had one.
As mentioned in another post, their mobos are made specifically for them and alot of the time you cannot upgrade.
Oh, and the financing can be tricky, the wife has been having problems with her bill. I don't ask, she gets pissed and thinks I am giving her the "I told you so"
I thought there were some companies that build pc's with brand equipment, not sure though. Nothing is free and things are cheap for a reason, you get what you pay for