I hear ANUS laptops has a heck of a deal.
What I usually do is go to the three big guys, dell/gateway/and HP when I need to buy a simple computer, and go through the whole process for the cheapest extact same machine at each company, right up to the point where you buy it. So you have shipping, taxes, and everything calculated in the price, as well as an estimated delivery date if time is of a concern.
Then just buy the cheapest, they will usually be within $20-50 of each other.
If you want a gaming or performance rig, what I recommend is go to review sites and pick out everything you want from motherboards, processors, memory, hard drives, video card(s), etc. Once you have your list drawn up, go to the many tech forums on the web and search for the items you have picked out and make sure there are no known problems or incompatabilities.
Then head to pricewatch.com and buy the stuff at the cheapest places. Checking for known problems ahead of time will save you a lot of headaches when trying to be on the bleeding edge of technology.