I'm on my second Dell desktop, bought my first one in 2002, and it ran like a tank, and I only ended up replacing it in 2008 because I wanted something faster. My wife's Dell desktop has likewise been great to work with. We just bought a Dell Zino HD to run Hulu and Netflix on the TV. What's even better is that every single one of these machines (except for my 2002 desktop) was a refurb or scratch and dent from the Outlet, so I paid maybe 70% of the normal price.
One time a client I worked with ordered eight Dell desktops in an effort to update his office. One of the monitors was a little wonky - I called up Dell, and they overnighted a new monitor.
Just because I have had a really good experience with Dell doesn't mean I think everyone else is full of it - a friend of mine did laptop repair for a living and swears Dell are crap. However, given my experience, I still recommend Dell to my friends.