disclaimer: My day job is in a government IT group that supports about 200 mixed servers (Unix, Linux, Microsoft) and about 4000 desktops and laptops (Windows). I used to spec the Microsoft servers. My opinions are my own.

background: We used to use Dell servers, 2400 series, and switched after the 2500 series was introduced because their RAID system was unreliable in our experience. The Dell 240 desktops were much more reliable, and we used them as servers where we didn't need raid. I built a Citrix farm out of them, about 25-30 servers. The Dell reps were surprised to see this, to say the least. On our next run of servers we purchased HP DL360's and 380's, which have been great for us. Dell support is uniformly lousy, IMO.

opinion: For all the vendors, product life cycles are very short, so testing time is short. There are models of computers by any manufacturer that have problems. For Dell 380's, it's bad DVD/CD drives. For a newly released model, nobody, included the manufacturer, knows how reliable it's going to be. Service at the consumer level sucks. It probably has to suck, because too many consumers have no clue of how to operate a computer, and the manufacturers are stuck fielding thousands of calls that have nothing to do with a problem in the hardware. The better their support is, the more calls they would get (conjecture).

suggestion 1: Buy a name brand pc with the most memory and slowest Intel processor you can find in their entry level line. The faster the processor, the more the heat, the more heat the more stress and reduced lifetime on everything. You won't notice a 50% improvement in CPU speed unless you're playing intense video games or doing multi-hour calculations. Every version of Windows ever written needs large amounts of memory.

suggestion 2: Buy a refurbished name brand business computer. Dell Optiplex's are what we use, and they've been very reliable for us. The parts in these business machines, IMO, aren't any better than those in a consumer PC. The benefit for the business is remote management and diagnostics, and theoretically faster repair because of modular design. A probable benefit is that they have a longer product cycle, and are more reliable because of that.

Best of luck with whatever you choose.