I agree about Dell being good machines. I've always bought them, never had a problem. I liken them to Ford tractors, never going to win any prizes for looks but very solid workers.
I use them out of the box, an i5 chip and 8MB ram, works a treat but I don't number crunch etc.
And everytime over the years I've bought a custom made machine (not dell) I've had problems.
One tip for buying dell (in the UK, maybe the same in the US). They love to play tricks on their website, so the same computer they sell in retail might be cheaper if you buy it through their business channel. So TAKE YOUR TIME when ordering and expect tricks on their website, but if you do it right you'll get a great machine for a good price.