I'm always impressed with Dell's build quality.
aye, i'll second Dells for generally tanklike construction and quality.....once you get past the cheaper models that is..lol
(but then thats the same with most companies)
also in their top tier XPS and the range directly below that, they use some seriously well picked mobos and PSU's.......mind you, when you consider the quantity they buy in, i can see them getting first pick from the bins...heh
if you want a ready built PC, get the Dell, although get it with the cheapest graphic card option, then buy an aftermarket one from somewhere like overclockers.co.uk or scan.co.uk and fit it in yourself, it really is not difficult and will save you a fortune over what Dell charge for them....
the nicest thing about the Dells is the lack of BSOD (Blue Screen of Death).....in the 4 Dells i owned i rarely saw a BSOD, usually when i'd forced something myself way past what most people would know they could attempt......since i've built my own PC i've had more BSOD's in about 3 weeks
configure a setup on the website, then phone up with the price the website quotes, if the model you are looking at is around £1k-1.5k you should if good be able to negotiate either £50-100 more off the price or get them to add on that much in extra stuff (usually what they prefer to do)