I would pick Asus. They are able to use many of their own branded components and being the new kid on the block, they have to try harder. Many of their machines have good specs and, of course, Asus motherboards which I have come to prefer. I see nice "bundles" for Asus PC's with Asus branded wide screen monitors that are very tempting at Fry's, other big box retailers.
I personally will not buy a PC unless the Windows DVD comes with it. To my knowledge, none of the "major national brands" offer the Windows DVD with their machines. In many cases you don't even get recovery CD's any more. The recovery program is on a partition on the hard drive and if the hard drive goes out . . .
J.