Myself, I don't even consider any brand that isn't Apple, Lenovo, Dell, or Toshiba. Those are the only ones I even bother looking at, because they have a long standing reputation for quality. I had an Apple iBook G4 that served me exceedingly well for 5 years. About the worst that happened to it was it developed a small hairline crack on one corner of the case. I finally retired it because the system just couldn't keep up with my expanding needs. I passed it on to my parents who really just wanted something they could use for web browsing and email in hotels when they travel.
Before that I had a Dell Inspiron laptop that also worked exceedingly well, and my current Dell Studio 17 laptop is also working out quite nicely.
I also tend not to buy things in a brick and mortar store if I can help it. I'll make exceptions when I need something right now, like when I moved 1500 miles, and UPS manhandled my old computer into oblivion. Getting them to pay up on the insurance claim was also not exactly a pleasurable experience. So in that case I bought something at a local Best Buy. I also stumbled across a pretty good deal on a Dell Studio Slim Desktop at Microcenter. It was an open box, but it's working pretty well, and it's primary job is just to be a HTPC, as well as emulator for some of my old PSX and SNES games. (Only the games I actually own) So I jumped on that too, but typically I only buy online because you get far better deals, and you can buy the extended warranties through the OEM, not the store. Store based extended warranty programs... Let's just say that the only real value to them is if you should run out of toilet paper. Also, don't bother with services like Geek Squad. If you can't find the help you need on places like this, odds are there's a kid living in your area who could do it for a fraction of the price, and then you promote good will in the community. You save some money, the kid gets a little spending cash, you're helping promote employable skills for the kid's future, and you keep the kid out of his/her parent's hair for an hour or so. Everyone wins, except the Geek Squad people who have a tendency to go rifling through your system looking for pictures/music/movies/software they may want a copy of, as well as taking a small problem and making it worse through sheer incompetence.
So if you're looking to buy a system, go direct to the manufacturer. If you're looking to build your own, I generally don't even bother looking beyond NewEgg anymore. They may not always be the cheapest, but you always get what you order, it's delivered on time, they are very up front about their different return policies, and prices are always competitive even if they aren't the cheapest. They're also generally very good at providing the technical specs you need to make sure it's really what you want.
And finally, what I meant by that saying, is that I'm a very harsh critic. Few things meet with actual praise from me. Generally the best rating something can get, is that it works for what I need it to do. Although I have a new appreciation of my 09 Corolla after I've had to drive this rental 2010 Ford Fusion SE for about the past week while my car is being repaired after suffering damage at the hands of some idiot on California's roadways. For one of the best American sedans out there, IMO, the Fusion is a steaming pile. Maybe the Hybrid models are better, but the one I have blows every farm animal that ever is, was, or will be. But I digress. Point is, I tend to have extremely high standards that are very hard (if not impossible) to meet, so the fact that Vista gets a fairly neutral rating from me is pretty good.