I build my own when it comes to desktops. Laptops, however, I would rank as so:
Brands that are good and would make the list, but aren't as well known: Alienware and Sager...both good, both overpriced. Personally I would stay away from Asus...I can't stand nor do I trust their m/b's which gives me very low faith in their ability to build a worth-while laptop.
In 1993, I have an IBM PS2 386. It broke. My mom bought it on QVC. As it was disontinued, and they didn't want to repair it, she actually got a full refund after 8 months.
Then bought a Gateway 2000. That thing SUCKED! I learned how to repair and build computers because they sent the repair tech out to my home so many times. I bitched, and they gave me a refund after 10 months of that crap.
Bought a Dell Pentium 90 in 94 or 95 (I forget). At the time, it was top of the line, and I think I spent $3,000 on it, or close to that (with the monitor). That think sucked. I kept breaking. After hassling with my schedule to get the tech to come to my house, I finally just started replacing the parts myself.
What sucked is that quite often - the tech would come over to fix the Dell, and the replacement parts had been shipped to me. HE would open the box, and already the parts were broken themselves - or would not work properly. So, Dell would send replacement parts to replace the replacement parts. After several months of that crap, I managed to complain enough to get all my money refunded, except for the extended warranty I had bought for $200.
I used THAT money to buy 2 computer by that point. A Micron Pentium 90 (which was cheaper by then) and a Midwest Micro 486. That Micron was the FIRST computer I had owned that never gave me a problem. The Midwest Micro had tons of video card issues. I later upgraded that 486 with a pentium mortherboard, and we just kept the case.
I then bought a Quantex in the late 1990s... - I LOVED That system. GREAT computer - never broke (I gave it to my sister a few years back - It STILL works after probably 9-10 years).
I bought an HP to replace it about 4 years ago. Worked fine until it got surged out of existance (despite a $50 surge protector) last summer. I am on my 2nd HP.
Quantex does not exist any longer after the internet stock boom ended. Micron is not the same PC company that it was (if it is even still around). I won't buy another Dell or Gateway.
Every time someone asks me what laptop to buy I try and talk them out of buying a laptop altogether. Most people who think they need a laptop don't.
For desktops get what you want as long as it isn't a E-machine but get the longest parts warranty possible when you buy it. Every manufacturer has problems at some point. We have piles of Dell computers with swollen capacitors stacking up in our office.
Lenovo is best in my book for support, at least as a self service provider at work. Their parts ordering process is way better than most.
Gateway used to be good, but now the went with MPC for support, so they suck.
Never liked Dell support. I saw two brand new "workstation" class (similar to server class) machines come DOA. Both were dual or quad xeon processors with lots of RAM. Took Dell 3 weeks to straighten one of them out, even with them sending a technician to install the parts.
For laptops, I have always recommended Thinkpads. We never had major issues with them compared to some of our Gateway laptops.
I have an HP laptop at home that has had no issues in three years except for a few keys that "fell off" according to my wife and son (I think the dog stepped on it). For a $600 laptop after rebate, I cannot complain about the HP.
I've had good luck with Dell. My laptop survived the heat and dust of Iraq with no problems (thanks in part to a pelican case). My desktop has been a top notch machine (XPS). I've built my own in the past but they never turn out as quiet or efficient in cooling as the Dell machines. I know a few people who have had problems, but it's rare and support takes care of them.