Dell's fine. I enjoy bashing Dell here and there, but in reality they do offer very good prices on their products. And if you take correct care of the computer, and administer to it correctly, then everything will be fine and you'll end up saving alot of money. Note, though, that if your product is one of the few that ends up with a problem, Dell's customer's service isn't close to being up to par with Apple's.
The thing is, that some people would rather sink in more money and have a computer that they know will be fine, and will barely need any upkeep. Paying for peace of mind. And in my opinion, peace of mind is really worth the hundreds of dollars we pay as premium for our apple computers. But for others, it's not. To each his own.
If you can build your own computer, that'd be great. Saves a ton of money, but that's only if you know how to do it. My friends have built incredible gaming machines by themselves, and have saved hundreds of dollars.