There are 2 schools of thought:
1. You buy based on the warranty, phone support, etc.
2. You buy assuming you will support it yourself, and are only concerned with parts warranties.
If you are #1, buy Dell.
If you are #2, I would buy from a place like
http://www.americancomputech.comYou get to pick the parts, they put it together, and the warranty is only on the parts.