Of the 4 computers we have in 'use', 2 are Dell's, one HP, and one Sony.
All are 'good', and in that I mean if there were problems, it wasn't because of the manufacturer but the components used.
Sony, had a hard drive fail within 3 years. Only problem it experienced.
HP, video card died after 4 years. Wireless mouse that came with it literally needed to be fed AA batteries twice a month... replaced the mouse.
Dell's, older one had CMOS battery go (never had this happen on other computers at any age) at about 4 years. Both RAID drives died after 4 years and within weeks of each other. WD to blame for this, not Dell.
Newest Dell, 2 years old I use daily, myriad of problems. I had a DVD drive destroy a CD and itself. Couldn't use my existing UPS, had to get a 'server' version to work with its PSU, and the media card reader 'disappeared' on me.
Dell service on both machines (these are XPS and the older one got US special service, the newer one XPS only service) was good in that 'they' sent someone out to do the 'work'. The only bothersome one was the media card reader. They (Dell) replaced the reader and then the motherboard (under 90 days of me getting the system) and it didn't fix it. I later discovered that is the power cord was removed it RESET the device and it worked fine until the next 'bad' shutdown (usually a BSOD, which DVDFlick caused often at that time). Dell has never fixed this problem.
Oh, I should tell you the older DELL was initially an XPS Gen3. I had a problem where for no reason the system fans would take off, it had 3 or 4 fans in it, I forget the count, but even with nothing happening it would sound like a bunch of high speed hairdryers were in it. Dell replaced the PSU, then the motherboard, then the whole machine with a Gen5.
I also have an very old Dell 8100 that is not in use now. It had a network problem with the built-in device. It would drop often. I was living in Austin at the time and had 'access' to some Dell employees and contacts. Dell replaced the motherboard and the problem was not solved. I was able to determine that the engineers knew about the problem. I gave info to Dell support on who to contact and I was sent a higher revision motherboard within weeks that fixed the problem.
I've been buying Dell's since then for the performance machine I want. My wife doesn't want to wait when she wants one and gets whatever looks good to her in the store.
NOTE: I always buy the extended warranty. Dell can be expensive for 4 years, but others we bought for my wife in Best Buy and Circuit City (no defunct) had much cheaper warranties. The HP is the only one that I'd say we 'lost' money on. The Dell's, well, most of the problems were within the 'standard' 1 year warranty but all machines have had calls before the warranty did expire.