You make a valid claim Fieldcenter, but not for everyone. For 90% of the community that uses tech support from Dell, HP, Acer, or any other major brand out there service is VERY hard to get. After spending hours on the phone with their technical support convincing them that something actually is wrong with your system, they tell you to back up your data and send your computer in. Well, half the time you can't get back in to your computer to back things up, so lets just hope that you have a recent backup or you will lose EVERYTHING. Then, hope that they will send you out a return box and shipping label. In many cases, they won't and you will have to provide the original shipping box and pay for shipping to them. Then wait a week until your computer is next in line to be repaired, then another week for them to replace it, send it back out through distribution, and have UPS or FedEx deliver it again. All of this to replace a faulty hard drive.
Why do I describe this? Because I get to enjoy it about once a month while working in my computer business. People with systems from Dell, HP, Acer, etc. that are still under warranty and want it warranty repaired have to go through the above process and I deal with it all the time. However, in my case if a piece goes bad on my system, I can rip into it right there, swap out the part and test, and put in new hardware immediately and eliminate two weeks of downtime.
Even if you do take your computer to a local shop, it's not going to guarantee that the service will be correct or faster. One customer I had previously had his computer at the Geek Squad in our nearest Best Buy. After more than a week of waiting, he finally got his computer back. They said they had to change the boot order and some BIOS settings and test the system stability and gave him a huge invoice for it. But when he took it home things still wouldn't work. $400 worth of charges and several more trips back and forth to the Geek Squad and he finally gave up and came to me. Within ten minutes looking at his computer I could tell that he had a faulty motherboard and needed replaced, but nothing that should cost him $400 and several weeks to figure out!
As to the original question, though. For desktop computers I always will prefer custom built for myself, but I know that some others may not want to go that path. I just highly recommend that anyone that goes with a pre-built system at least stick with the Business line of computers from Dell or HP. Their consumer line is built so cheaply. And no matter what Dell or HP computer you buy you're probably paying much more for less performance than a custom-built system anyways with higher quality. For notebooks, I have worked with several HP ProBook and EliteBook notebooks and love them. I don't use a laptop anymore enough to warrant purchasing one for myself, but if I did that would be what I would go with. The highest quality I have seen in any notebook (including HP Envy and Mac laptops) with incredible customer service and unbeatable performance hardware for design work. However, if you're wanting more of a gaming laptop then I would suggest ASUS or even better Clevo/Sager power notebooks. They are very high quality as well, and have the highest performance components available on the market. I owned a Clevo D900K notebook for five years. That notebook had a desktop dual-core Athlon processor in it back when dual-core processors were first released, and while it was too big to be a portable notebook, that thing still survived a lot of travel plus nearly 24/7 use for those five years and continued trucking on to the end until one of its two hard drives finally gave out.