On the flip side, even though I am an experienced PC Builder(done about 12 for myself, 10+ for friends and family and about 10 for work)...I did purchase 2 pre-built machines and both were Dells. I had and used these machines from about 2001 to 2006. I did experience a problem with a video card once. I did have to speak on the phone for about 2 hours with tech support, but ended up with a free upgrade from an Nvidia 6800 to an ATI Radeon X800XT. That was a jump from a $200 card to a $500 card. Then, near the end of my warranty, the fan in my X800XT started acting up. They immediately sent me another X800XT. Finally, I had a power supply go outside of warranty on a Dimension 4550. I called them and got a new PSU for about $30. Piece of cake.
So, just wanted to share that not everybody who has owned a Dell in the past feels like they have had a horrible experience.