Dell isn't for everybody but it is a viable option for a lot of people. Here is my list of when Dell is for you and when they aren't.
If you want to rip out the motherboard and the psu, Dell might not be your best option.
If you want to overclock, dell is not for you.
If you want an Amd chip, Dell might not be the best option.
If you want tech support, Dell is for you.
If you want great tech support, Dell isn't for you.
If you buy a Dell 2400 and try to install an agp video card and complain that it wont work, chances are you should buy another Dell because there is no way your going to be able to figure out what parts to buy and install them correctly.
If you want to upgrade the video card, hard drive, sound card, optical drives and memory Dell is for you.
If you come here and complain about sound card options, Dell is for you, because chances are you will have a hard time installing a sound card yourself.
If you have been on AT for over a month and complain that Dells are over priced Dell is for you, because if you can't find a good deal on a Dell you won't be able to find a good deal on anything.
Dell has it's downside, if you want to get ripped off just call them and ask them to build a computer for you and they will take all your money. If call Dell for anything chances are you will speak to about 10 people and get transferred about 20X. They are a huge company and if you want tech support you will be speaking with somebody with a heavy Indian accent.
On the upside if you watch hot deals you can get a fast computer for a lot less than you can build yourself, they will give you a year tech support. If you buy a 4600/8300 they are highly upgradeable and I love the clamshell case, the computers are whisper quite.
Tom