Dell has sold a few good PC's so long as you just stay within the predefined functions of that PC.
in other words, if its in the office area, use it for office stuff only.
however, i did have a huge problem with a Dell PC i was workin on with a friend. it was an XPS 7** [forget the model number, 760 maybe?] they had the processor i7 overclocked to about 3.7gHZ, way to high for system stability because it went down as soon as a game pulled up. After replacing the whole entire PC 1 component at a time, after i had told them it was their setup, they finally sent out a new one with the same problem. This new one they sent out was 3.7gHz as well, so we sent it back. The third one that came out worked like a charm, nice and fast. 2x GTX285's and 4 Gigz DDR3 ram. however, the processor was 3.4ghz OC'd.
I really hope they be more careful next time i see anyone buy an XPS model, i mean honestly putting it at the tippy top of the performance graph is ok but if it even goes over an inch it falls into instability. I do note however that the 2 cards were placed right on top of eachother and ran about 84C in game. It was stable i guess, just a little warm. i dont understand sacrificing quality for the sake of a little extra noise in the system. that's mainly why i dont trust dell i guess.