|Inferior electronic components are the main reason for hardware failure. The desire to reduce costs led manufacturers to buy cheap components. Often that led to early failure of those components. Capacitors were probably the worst (best?) example:|
Yes, Dell and Emachine were bad about that but their motherboards were OEM from regular motherboard manufacturers. I don't think HP and gateway had as big a problem with that. Many HP motherboards were made by Asus and gateway often used Intel motherboards.
I don't know if there's any way to know to what extent bad components still plague computer motherboards. but if you go by history then HP or gateway would be something to look at.
The problem with power supplies is both bad components and the fact they were often underpowered so again, early failure was not uncommon. Also, when a power supply fails it often ruins the motherboard as well.
Just about every system manufacturer had some models that used proprietary power supplies. The connections would be the same as all other power supplies but they were physically sized differently so you couldn't upgrade to just any power supply--it had to be a special fit.
The obvious solution is to buy a model that uses the generic size so replacement is easy. Then go ahead and buy the computer as well as a high quality power supply to swap into it. If it's a new machine you might need that done in an approved shop so the warranty isn't violated.
You should probably have some kind of backup system set up too--either an external hard drive or you could subscribe to one of those online backup services--as your hard drive will eventually fail.
Oh, and you'll want a high quality surge protector and maybe a UPS.