I am really not a Dell Or HP fan, but choices recently became more limited and they are pretty much who is left. Well, e-machines. see?
I have a similar position. I'm finding it much cheaper and better to build your own computer. Dell often uses cheap parts instead of the brand name like Asus, Corsair, etc. Building a computer takes less than two hours and installing windows maybe one extra hour. Another benefit is that there is no bloatware (unnecessary software) that is often packaged with Dell, Acer etc. Another benefit it the warranties of the individual parts in a custom built computer. Often lifetime warranties on RAM, 3-5 years on hard drives, etc. You pick and choose quality components.